europaea BCCP (Em=+70, +130 mV) (Shimizu et al., 2001), which lacks the distal ligand for the heme molecule with the lowest reduction potential but not to that of R. capsulatus BCCP (Em=−190 to −310, +270 mV) (De Smet et al., 2001) and P. aeruginosa BCCP (Em=–330, +320 mV) (Ellfolk et al., 1983). Thus, relatively high Em value of the lowest potential of the heme would be explained by the fact that the amino acid sequence of QPO that apparently lacks distal ligand of the heme in the middle portion. This idea would be supported by the previous observation showing five-coordinated heme c exhibits higher Em value than that of six-coordinated

heme c (Marboutin et al., 2006). However, although five-coordinated heme c have lower extinction coefficient (Marboutin et al., 2006), the relative spectral contribution of the each heme in QPO was nearly same. Further experiment is needed ABT 199 to address the coordination of heme in QPO. In the present study, we established GPCR Compound Library cell assay a system for the overproduction and purification of rQPO to build a base for biophysical research

on QPO. Moreover, we initially measured the midpoint electron potentials for all the heme molecules in the triheme peroxidase. Biochemical analysis for the triheme c peroxidase has recently been undertaken. The results of our study will trigger further studies on QPO, including mutant analyses, and will help elucidate the mechanism underlying quinol–protein interaction and/or interaction among the three heme molecules in

QPO. This work was supported by a Grant-in-Aid for Young Scientists Carnitine palmitoyltransferase II (B) from the Japan Society for the Promotion of Science (#19791353 to E.T.) and by a Grant-in-Aid for Scientific Research (C) from the Japan Society for the Promotion of Science (# 21592346 to K.K.). “
“Brucellosis is a major zoonotic disease caused by pathogens of the genus Brucella. The eradication of brucellosis in domestic animals, associated with the prevention of human infection, can be attained through accurate diagnosis. However, the conventional serological diagnosis of brucellosis has limitations, particularly in detecting the infection period. Accordingly, the aim of this study was to determine reliable immunogenic proteins to detect Brucella abortus infection according to time course responses to aid in the appropriate management of this disease. Proteomic identification through two-dimensional electrophoresis (2DE), followed by immunoblotting, revealed 13, 24, and 55 immunodominant B. abortus 544 proteins that were reactive to sera from experimentally infected mice at early (10 days), middle (30 days), and late (60 days) infection periods, respectively. After excluding several spots reactive to sera from Yersinia enterocolitica O:9-infected and noninfected mice, 17 of the 67 immunodominant proteins were identified through MALDI-TOF MS.

More recently, C. vulgaris NJ-7, a strain isolated from the Antarctic, was used to investigate the adaptation of eukaryotic microbes to permanently cold environments (Hu et al., 2008; Li et al., 2009). The strain NJ-7 possesses the same 18S rRNA gene sequence as that of UTEX259, a strain isolated

from the temperate region, but shows a significantly intensified freezing tolerance (5- to  1000-fold higher viability) than the temperate strain. Comparative studies of the two C. vulgaris strains provide opportunities to understand how intra-species check details evolution is undertaken in eukaryotic microbes to adapt to the Antarctic or other extreme environments. HIC6 is a group-3 late embryogenesis abundant (LEA) protein found in C. vulgaris. Together with HIC12, it was first identified by 2D-HPLC and SDS-PAGE to be hardening (cold treatment)-induced in the strain C-27 (Honjoh et al., 1995). Its cDNA was also identified by differential screening of a cDNA library (Joh et al., 1995) or suppression subtractive hybridization (Machida et al., 2008). LEA SGI-1776 nmr proteins were initially found at the late stage of embryogenesis in cotton (Galau et al., 1986) and were subsequently found in algae (such as C. vulgaris), cyanobacteria (Close & Lammers, 1993), nematodes (Browne

et al., 2002) and fungi (Abba’ et al., 2006). The proteins can be divided into different groups on the basis of similarities in amino acid sequences (Colmenero-Flores et al., 1997; Cuming, 2005; Battaglia et al., 2008). Like many other LEA proteins, HIC6 remained soluble under boiling conditions and showed in vitro cryoprotective activities on lactate dehydrogenase (LDH) (Honjoh et al., 2000). Overexpression of HIC6 in plant or yeast could enhance their freezing tolerance (Honjoh et al., 1999, 2001), and

in the transgenic plant, HIC6 was localized to mitochondria (Honjoh et al., 2001). In strains NJ-7 and UTEX259, the encoding gene hiC6 was also induced upon exposure to cold, and the expression was intensified in strain NJ-7 in comparison with UTEX259 (Li et al., 2009). These results suggest that the enhanced expression of hiC6 is probably involved in the development of freezing tolerance in C. vulgaris. The intensified expression of hiC6 in NJ-7 could be due to gene duplication, increased transcription or post-transcriptional regulation. PIK3C2G In our previous study, only one hiC6 gene was identified in each of the two Chlorella strains, NJ-7 and UTEX259 (Li et al., 2009). In the present study, however, sequencing of that chromosomal region revealed that multiple hiC6 genes are organized in tandem in both strains. The tandem-arrayed genes encode different HIC6 isoforms and are differentially expressed. Chlorella vulgaris strains were grown in BG11 (Stanier et al., 1971) in the light of 50 μE m−2 s−1 at 20 °C with aeration. Cells grown at 20 °C were cooled to 4 °C in a water bath and transferred to a 4 °C refrigerator with aeration and illumination (50 μE m−2 s−1) for different periods of time.

More recently, C. vulgaris NJ-7, a strain isolated from the Antarctic, was used to investigate the adaptation of eukaryotic microbes to permanently cold environments (Hu et al., 2008; Li et al., 2009). The strain NJ-7 possesses the same 18S rRNA gene sequence as that of UTEX259, a strain isolated

from the temperate region, but shows a significantly intensified freezing tolerance (5- to  1000-fold higher viability) than the temperate strain. Comparative studies of the two C. vulgaris strains provide opportunities to understand how intra-species AZD2014 mouse evolution is undertaken in eukaryotic microbes to adapt to the Antarctic or other extreme environments. HIC6 is a group-3 late embryogenesis abundant (LEA) protein found in C. vulgaris. Together with HIC12, it was first identified by 2D-HPLC and SDS-PAGE to be hardening (cold treatment)-induced in the strain C-27 (Honjoh et al., 1995). Its cDNA was also identified by differential screening of a cDNA library (Joh et al., 1995) or suppression subtractive hybridization (Machida et al., 2008). LEA GSK2118436 cost proteins were initially found at the late stage of embryogenesis in cotton (Galau et al., 1986) and were subsequently found in algae (such as C. vulgaris), cyanobacteria (Close & Lammers, 1993), nematodes (Browne

et al., 2002) and fungi (Abba’ et al., 2006). The proteins can be divided into different groups on the basis of similarities in amino acid sequences (Colmenero-Flores et al., 1997; Cuming, 2005; Battaglia et al., 2008). Like many other LEA proteins, HIC6 remained soluble under boiling conditions and showed in vitro cryoprotective activities on lactate dehydrogenase (LDH) (Honjoh et al., 2000). Overexpression of HIC6 in plant or yeast could enhance their freezing tolerance (Honjoh et al., 1999, 2001), and

in the transgenic plant, HIC6 was localized to mitochondria (Honjoh et al., 2001). In strains NJ-7 and UTEX259, the encoding gene hiC6 was also induced upon exposure to cold, and the expression was intensified in strain NJ-7 in comparison with UTEX259 (Li et al., 2009). These results suggest that the enhanced expression of hiC6 is probably involved in the development of freezing tolerance in C. vulgaris. The intensified expression of hiC6 in NJ-7 could be due to gene duplication, increased transcription or post-transcriptional regulation. Vitamin B12 In our previous study, only one hiC6 gene was identified in each of the two Chlorella strains, NJ-7 and UTEX259 (Li et al., 2009). In the present study, however, sequencing of that chromosomal region revealed that multiple hiC6 genes are organized in tandem in both strains. The tandem-arrayed genes encode different HIC6 isoforms and are differentially expressed. Chlorella vulgaris strains were grown in BG11 (Stanier et al., 1971) in the light of 50 μE m−2 s−1 at 20 °C with aeration. Cells grown at 20 °C were cooled to 4 °C in a water bath and transferred to a 4 °C refrigerator with aeration and illumination (50 μE m−2 s−1) for different periods of time.

0%). The Framingham equation predicted a higher cardiovascular risk compared with the Rama-EGAT and D:A:D equations, which

seemed to agree relatively well. Only d4T use was marginally associated with a high Rama-EGAT score; longer ART duration and current viral suppression were significantly associated with a high Framingham score. The low predicted cardiovascular risk in our cohort can probably be explained by the similarly low prevalence of cardiovascular risk factors. A low prevalence of cardiovascular risk factors in a Thai population was previously described in the EGAT study [7], although the data were collected over 20 years ago. The prevalences of hypertension, hypercholesterolaemia, diabetes and smoking in a similarly aged (mean this website 43 years) group of HIV-uninfected Thais in 1985 were 18, 32, 6 and 42%, respectively, compared with 13, 24, 7 and 13% in the present study. The lower prevalence of risk factors in our study may reflect http://www.selleckchem.com/products/epacadostat-incb024360.html under-diagnosis (hypertension), undocumented treatment (hypercholesterolaemia), the effect of smoking cessation campaigns, and the lower proportion of male subjects. CHD was an important cause of death in the EGAT cohort (28 of 165 deaths over 12 years of follow-up); the overall prevalence

was not reported. To our knowledge, this is the first study to evaluate the Rama-EGAT and D:A:D equations in an HIV-infected Asian population. The Rama-EGAT Heart Score comes from the EGAT study, which followed 3499 HIV-uninfected Thais aged 35 to 54 years employed at the EGAT from 1985 to 1997 [7,10]. The risk equation published by the D:A:D Study Group was derived from a data set of 22 625

HIV-infected subjects in 20 countries across Europe and Australia [11]. That the cardiovascular risks predicted by these equations agreed relatively well suggests that HIV-infected Thai individuals may not be at increased risk for CVD compared with those without HIV infection. Furthermore, the lack of statistically significant associations between HIV-related factors and high Rama-EGAT scores suggests that traditional cardiovascular risk factors may be interpreted similarly in HIV-infected and uninfected populations, a conclusion also drawn from the D:A:D study [11]. Rama-EGAT risks were, in fact, slightly higher than D:A:D risks; this may be explained by the broader cardiovascular outcome definition used in the Rama-EGAT see more equation (MI or invasive coronary procedure in Rama-EGAT vs. only MI in D:A:D). This study has several limitations. First, cardiovascular risk data were obtained by physicians using a form with open-ended questions, allowing misinterpretations. ART histories were complex because of treatment changes and interruptions. Lipodystrophy was not defined by standardized criteria; however, it was assessed by experienced physicians at HIV-NAT with most subjects having at least one obvious sign (i.e. facial or buttock fat loss, increased abdominal girth, or prominent veins).

0%). The Framingham equation predicted a higher cardiovascular risk compared with the Rama-EGAT and D:A:D equations, which

seemed to agree relatively well. Only d4T use was marginally associated with a high Rama-EGAT score; longer ART duration and current viral suppression were significantly associated with a high Framingham score. The low predicted cardiovascular risk in our cohort can probably be explained by the similarly low prevalence of cardiovascular risk factors. A low prevalence of cardiovascular risk factors in a Thai population was previously described in the EGAT study [7], although the data were collected over 20 years ago. The prevalences of hypertension, hypercholesterolaemia, diabetes and smoking in a similarly aged (mean Akt inhibitor 43 years) group of HIV-uninfected Thais in 1985 were 18, 32, 6 and 42%, respectively, compared with 13, 24, 7 and 13% in the present study. The lower prevalence of risk factors in our study may reflect Metabolism inhibitor under-diagnosis (hypertension), undocumented treatment (hypercholesterolaemia), the effect of smoking cessation campaigns, and the lower proportion of male subjects. CHD was an important cause of death in the EGAT cohort (28 of 165 deaths over 12 years of follow-up); the overall prevalence

was not reported. To our knowledge, this is the first study to evaluate the Rama-EGAT and D:A:D equations in an HIV-infected Asian population. The Rama-EGAT Heart Score comes from the EGAT study, which followed 3499 HIV-uninfected Thais aged 35 to 54 years employed at the EGAT from 1985 to 1997 [7,10]. The risk equation published by the D:A:D Study Group was derived from a data set of 22 625

HIV-infected subjects in 20 countries across Europe and Australia [11]. That the cardiovascular risks predicted by these equations agreed relatively well suggests that HIV-infected Thai individuals may not be at increased risk for CVD compared with those without HIV infection. Furthermore, the lack of statistically significant associations between HIV-related factors and high Rama-EGAT scores suggests that traditional cardiovascular risk factors may be interpreted similarly in HIV-infected and uninfected populations, a conclusion also drawn from the D:A:D study [11]. Rama-EGAT risks were, in fact, slightly higher than D:A:D risks; this may be explained by the broader cardiovascular outcome definition used in the Rama-EGAT PR-171 equation (MI or invasive coronary procedure in Rama-EGAT vs. only MI in D:A:D). This study has several limitations. First, cardiovascular risk data were obtained by physicians using a form with open-ended questions, allowing misinterpretations. ART histories were complex because of treatment changes and interruptions. Lipodystrophy was not defined by standardized criteria; however, it was assessed by experienced physicians at HIV-NAT with most subjects having at least one obvious sign (i.e. facial or buttock fat loss, increased abdominal girth, or prominent veins).

[26, 56, 57] Emerging evidence suggests that fluid and serum VEGF levels not only are elevated in RA patients with hypoxic conditions but also by pro-inflammatory cytokines IL-1 and TNF-α.[58] Currently, VEGF and its receptors are the best characterized system in the angiogenesis www.selleckchem.com/products/MLN-2238.html regulation of rheumatoid joints. The VEGFRs on EC membranes consist of the tyrosine kinases VEGFR-1 (Flt-1), VEGFR-2 (Flk-1/KDR) and VEGFR-3 (Flt-4). KDR is a main mediator of angiogenic,

mitogenic and permeability-enhancing effects of VEGF. Moreover, KDR is up-regulated in response to hypoxia, a main inducer of VEGF gene transcription.[59] It is demonstrated that hypoxia stimulated VEGF-A (the most important member of the VEGF family) and VEGFR-1 expression decrease VEGFR-2 levels in ECs. During hypoxic conditions, plasma membrane VEGFR-1 levels are elevated, while VEGFR-2 levels are depleted. One functional consequence of hypoxia is a decrease in VEGF-A-stimulated and VEGFR-2-regulated intracellular signaling along with lowered EC NOS activation. In addition,

the capillary, arterial and venous ECs subjected to hypoxia display a decreased cell migration in response to VEGF-A. A mechanistic elucidation is that VEGFR-1/VEGFR-2 ratio is substantially increased during hypoxia to obstruct VEGF-A-stimulated and VEGFR-2 regulated endothelial responses to magnify cell recovery and viability.[60] In another study, Eubank et al. in 2011 showed that hypoxia can selectively stimulate anti-angiogenic molecule expression in mononuclear

phagocytes in a granulocyte macrophage colony-stimulating factor (GM-CSF) SB431542 enriched environment. The soluble VEGFR-1 (sVEGFR-1) is one of these molecules that act as a negative regulator for VEGF activity through VEGFR-2. Therefore, anti-angiogenic molecules can effect proliferation, migration and survival of ECs.[61] Placenta growth factor is another angiogenic factor and highly homologous with VEGF. PLGF can exert its angiogenic RANTES effect by synergizing with VEGF. However, it does not have an effect on lymphatic vessel functionality.[62, 63] Furthermore, PLGF can promote the production of VEGF from monocytes and macrophages.[64] It has been recently reported that PLGF is highly expressed in synovial tissue and enhances the production of pro-inflammatory cytokines, including TNF-α and IL-6.[65] Oncostatin M (OSM) belongs to the IL-6 subfamily and is mostly produced by T lymphocytes. High levels of OSM are detected in the pannus of RA patients and it may rise the inflammatory responses in joints and eventually lead to bone erosion.[65] OSM promotes angiogenesis and EC migration, and potentiates the effects of IL-1β in promoting extracellular matrix turnover and human cartilage degradation.[66] It was also demonstrated that OSM increased messenger RNA (mRNA) and protein levels of PLGF in a time- and concentration-dependent manner in RA synovial fibroblasts.

Thus, we propose that the enhanced surround inhibition shortly after visual cortical lesions may prevent hyperexcitability

in the sSC local circuit, contributing to reconstructing the finely tuned receptive field organization of sSC neurons after the visual cortical lesions. “
“Neuroimaging studies of humans have provided inconsistent evidence with respect to the response properties of the fusiform face area (FFA). It has been claimed Selleck Galunisertib that neural populations within this region are sensitive to subtle differences between individual faces only when they are perceived as distinct identities [P. Rotshtein et al. (2005)Nature Neuroscience, 8, 107–113]. However, sensitivity to subtle changes of identity was found in previous studies using unfamiliar faces, for which categorical perception is less pronounced. Using functional magnetic resonance adaptation and morph continua of personally familiar faces, we investigated sensitivity to subtle changes between faces that were located either on the same or opposite sides of a categorical perceptual boundary. We found no see more evidence for categorical perception within the FFA, which exhibited reliable sensitivity to subtle changes of face identity whether these were perceived as distinct identities, or not. On the contrary, both the posterior superior temporal sulcus and prefrontal cortex exhibited

categorical perception, as subtle changes between faces perceived as different identities yielded larger release from adaptation than those perceived as the same identity. These observations suggest that, whereas the FFA discriminates subtle physical changes

of personally familiar faces, other regions encode faces in a categorical fashion. “
“Specialized populations of choroid plexus epithelial cells have previously been shown to be responsible for the ALOX15 transfer of individual plasma proteins from blood to the cerebrospinal fluid (CSF), contributing to their characteristically high concentrations in CSF of the developing brain. The mechanism of this protein transfer remains elusive. Using a marsupial, Monodelphis domestica, we demonstrate that the albumin-binding protein SPARC (osteonectin/BM-40/culture-shock protein) is present in a subset of choroid plexus epithelial cells from its first appearance, throughout development, and into adulthood. The synthesis of SPARC by the lateral ventricular plexus was confirmed with real-time PCR. The expression level of SPARC was higher in plexuses of younger than older animals. Western blot analysis of the gene product confirmed the quantitative PCR results. The co-localization of SPARC and albumin shown by immunocytochemistry and its cellular location indicate that this glycoprotein may act as a recognition site for albumin. In addition, the numbers of SPARC-immunopositive cells and its expression were responsive to experimental changes of albumin concentration in the blood.

Our observations in Experiment I suggest that orientation processing in the spatiotopic reference frame can be modified by learning in favor of the trained stimulus relation and orientation. As neurons in the early

visual cortex are highly orientation-selective and are putatively engaged in encoding information about oriented lines on a retinotopic map (Hubel & Wiesel, 1959), we speculate that spatiotopic orientation representation could directly use such a retinotopic map. This hypothesis was tested by examining the relationship between spatiotopic and retinotopic location specificity of learning. Two groups of naive subjects were trained at 55° stimulus orientation under the congruent condition, in which the two successively displayed stimuli were centered on the screen. Roxadustat purchase During the training period, the second stimulus in a trial BGB324 manufacturer always fell in the left visual field (LVF) for one group of subjects, owing to a rightward saccade (first column in Fig. 2A, Group_LVF subjects, n = 6), but for the other group of subjects it always fell in the right visual field (RVF), owing to a leftward saccade (third column in Fig. 2A, Group_RVF subjects, n = 6). To examine

whether the spatiotopic learning effect observed in Experiment I could transfer to the opposite, untrained visual field, in the post-training test the subjects’ thresholds were measured

under four conditions that combined the trained and Sinomenine untrained visual fields with the trained (congruent) and untrained (incongruent) stimulus relations. Consistent with Experiment I, the mean thresholds in the trained (congruent) condition significantly decreased in both Group_LVF (pre-training threshold 7.84° ± 0.53° vs. post-training threshold 4.41° ± 0.32°, t = 6.00, P = 0.0019, paired t-test) and Group_RVF (pre-training threshold 7.53° ± 0.53° vs. post-training threshold 4.58° ± 0.27°, t = 9.54, P = 2.2 × 10−4). The post-training performance was better than in the untrained (incongruent) condition at the trained visual field location (t = 4.91, P = 4.7 × 10−4, left panel in Fig. 2B, pooled data from both groups of subjects, n = 12; for data from individual subjects, see Fig. 2C, left panel). For individual subjects, nine of 12 showed a significant spatiotopic preference in the post-training test (bootstrapping, P < 0.05). If the spatiotopic learning effect was independent of the trained retinal location, it would transfer to the opposite, untrained visual field. Contrary to this hypothesis, in the untrained hemifield there was no significant difference in threshold between the trained and untrained stimulus relations (t = 0.52, P = 0.61, right panel in Fig. 2B; for data from individual subjects, see Fig. 2C, right panel).

, 2001; Bochner, 2003). Detection and analysis is performed colorimetrically, which represents bacterial growth. GSK458 datasheet A tetrazolium dye is introduced into the medium and acts as the terminal electron acceptor during growth. Once reduced, the colorless dye turns violet, with a λmax of 590 nm. The intensity of dye is directly proportional to the amount of bacteria in the wells.

To verify the results from the rapid screening method, positive compounds (i.e. chemicals conferring resistance) were tested using both solid and liquid media. All stock solutions were stored at −20 °C in the dark. Additional strains containing their respective plasmids were tested simultaneously (Table 2). These included wild-type E. coli W3110, 5X RND, and W4680AE carrying pCusCFBA, pGesAB, pUH21, or pGEM-T. For liquid tests, all strains were precultured in Tacrolimus solubility dmso LB (containing 100 μg mL−1 ampicillin when necessary) to

an OD600 nm=0.6–1.0. Bacteria were then diluted to a final concentration of 5 × 105 cells mL−1 in LB and exposed to different levels of the test chemical. Dose–response curves were created by recording OD600 nm vs. concentration after 16 h of exposure. In solid media tests, compounds were diluted into cooling agar at different concentrations reflective of the levels present in liquid media tests. Escherichia coli strains W3110, W4680AD, W4680AE, or 5X RND carrying no plasmid, vector control, pCusCFBA, or pGesAB were streaked onto an agar plate, and minimum inhibitory concentrations (MICs) were determined. The responses to different classes of chemicals varied in the Biolog assay. Certain levels and/or chemicals were toxic to both strains (empty vector vs. vector containing), creating no response in the growth curves. For chemicals that had no effect on growth, the empty vector Beta adrenergic receptor kinase control and metal-exporter growth curves were identical, indicating no resistance exhibited by

expression of the respective RND-type metal export system. The growth rates of the expression of the RND-type metal export system exceeded that of the empty vector strain were recorded as conferring resistance. It was possible to approximate the MICs of an individual chemical using the Biolog assay based on the level of response. No metals were added to overexpress pCusCFBA and pGesAB in these experiments, and consequently, expression levels are likely to be low. Thus, it is possible that some potential substrates may not have been identified. Escherichia coli strain W4680AD (ΔacrA/B, ΔacrD) containing the control vectors (pGEM-T, pUH21) or metal exporters (pCusCFBA and pGesAB) were grown in LB medium supplemented with ampicillin, 100 μg mL−1, overnight at 37 °C. The inoculum was then diluted in IF-10 Base (Biolog part number 72264) to a concentration of 5 × 106 cells mL−1 (Bochner et al., 2001). A solution containing the cell suspension (1.2 mL), sterile water (18.8 mL, IF-10 Base (98.

The striking difference,

however, between FeS and the typical thioredoxin reductases is the absence of the catalytic site with the consensus, Cys-Ala-Thr-Cys-Asp (Fig. 1). As mentioned above, FeS shares 89% identity to the thioredoxin reductase-like protein (PDB ID: 2ZBW) from T. thermophilus HB8. The typical thioredoxin reductase from T. scotoductus SA-01 shares 69% identity with a thioredoxin reductase, for which the structure has also been solved (PDB ID: 2Q7V) (Obiero et al., 2006) from Deinococcus radiodurans. Both these structures are composed of an NAD- as well as an FAD-binding domain connected with an antiparallel β-sheet. Also noteworthy is the secondary structure similarity with regard to α-helices as well as β-sheets present in these two proteins. It has previously been shown that the thioredoxin reductase from E. coli undergoes a large rotational

conformation learn more change between two productive modes – firstly, for electron transfer from NADPH to FAD, and secondly, reduction of the disulphide bond between the redox-active cysteines by FAD (Lennon et al., 2000). Everolimus purchase This conformational change is thus essential for activity in thioredoxin reductases. Although the ferric reductase reported here has similar structural features compared with prokaryotic thioredoxin reductases, it is unknown whether it will undergo similar conformational changes. The gene encoding the typical thioredoxin reductase was located

in the draft genome sequence of T. scotoductus SA-01 and the translated protein sequence conformed to that typical of thioredoxin reductases as it possesses the redox-active motif known to be responsible for the final transfer of the reducing power to thioredoxin. The FeS and TrxB genes encode proteins with 335 and 325 amino acid residues and isometheptene predicted molecular masses of 36 147 and 35 132 Da, respectively. Good expressions of both heterologous proteins were obtained and the two-step purification procedure yielded homogenous protein preparations (Fig. 2) at sufficient concentrations for kinetic analysis. The two enzymes were analysed for their ability to reduce ferric iron (Fig. 3). It has previously been shown that flavin reductases are capable of the indirect reduction of ferric iron complexes (Coves & Fontecave, 1993; Woodmansee & Imlay, 2002). Others have also shown the reduction of ferric complexes by enzymes possessing bound flavin, including lipoyl dehydrogenase, NADPH-glutathione reductase, NADH-cytochrome c and NADPH-cytochrome P450 (Petrat et al., 2003). Considering the low redox potential of the FADH2/FAD couple (−0.219 V, E0 at pH 7) and the high redox potentials of most ferric complexes (Pierre et al., 2002), it is not surprising that flavoenzymes are capable of effective ferric reduction.