, 2000), cystathionine α-synthase (His-Cys, Ojha et al., 2000), cytochrome P450cam (Cys-H2O, Dawson et al., 1982) and NO synthase (Dawson et al., click here 1982; Tsai et al., 1996). In contrast, most cytochromes c participating in electron transfer have His/Met or His/His coordination (Wilks, 2002). The His/Cys coordination in heme c is known to be limited: the aforementioned

SoxAX, the 40 kDa triheme cytochrome PufC in the photosynthetic reaction center (Alric et al., 2004), and the 15 kDa DsrJ in sulfate respiration (Pires et al., 2006) have the axial coordination. NaxL and NaxS have no homology to these proteins in the primary structure and the physiological roles of these proteins seem to be distinctly different. Nevertheless, the His/Cys coordination in heme c might commonly contribute to the protein functions. One possibility of such a contribution is to create the very low redox potential of heme. The two hemes in a SoxA subunit of P. pantotrophus have low redox potentials: one is −432 mV and the other is lower than that (Reijerse

et al., 2007). The heme c in DsrJ is also reported to have a low redox potential. The relatively high σ-donor ability of thiolate ligand, Cys-, effectively stabilizes the ferric state of heme, and conceivable polar surroundings would make the heme–iron redox potential further lower. Taken together, NaxLS of the anammox bacterium strain KSU-1 appears to be a novel member of c-type heme proteins with His/Cys axial coordination and a low redox

potential. The low redox potential of NaxLS reminds Fulvestrant research buy us of its potential role as an electron transmitter in anammox bacteria, in which electrons with a very low redox potential are generated on oxidation of hydrazine catalyzed by HZO and/or HAO, or on ferredoxin oxidation–reduction that is supposed to occur in anammox processes in C. Kuenenia stuttgartiensis (Strous et al., 2006). The physiological role of the NaxLS protein has not been elucidated as yet and further investigation is required. Appendix S1. Procedure to determine the nucleotide 5-Fluoracil supplier sequence of metagenomic fragment containing genes for NaxLS. Please note: Wiley-Blackwell is not responsible for the content or functionality of any supporting materials supplied by the authors. Any queries (other than missing material) should be directed to the corresponding author for the article. “
“Three pathogens, Campylobacter, Salmonella, and Shiga-toxin-producing Escherichia coli, are leading causes of bacterial gastroenteritis in the United States and worldwide. Although these three bacteria are typically considered food-borne pathogens, outbreaks have been reported due to contaminated drinking water and irrigation water. The aim of this research was to develop two types of PCR assays that could detect and quantify three pathogens, Campylobacter spp., E. coli O157:H7, and Salmonella spp., in watershed samples.