Selenium-dependent growth of Treponema denticola: evidence for a clostridial-type glycine reductase.
Assessment of the nutritional requirements of Treponema denticola disclosed a strict growth dependence on selenium. In vivo labeling of cells of this organism with (75)Se and electrophoretic analysis revealed three labeled bands, two of which were selenoproteins correlating in size with subunits A and B of glycine reductase. Antibodies directed against glycine- or betaine-reductase subunits of Eubacterium acidaminophilum specifically also reacted with proteins from cell lysates of T. denticola. Moreover, ORFs within the T. denticola genome sequence were found whose products display high sequence similarity to glycine-reductase subunits. These findings strongly support the notion that T. denticola ferments amino acids via the activity of glycine reductase, an enzyme previously thought to be restricted to gram-positive bacteria.
Rother
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Institut für Genetik und Mikrobiologie der Ludwig-Maximilians-Universität München, Lehrstuhl für Mikrobiologie, Maria-Ward-Strasse 1a, 80638 Munich, Germany. Michael.Rother@lrz.uni-muenchen.de
Böck
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Wyss
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D000594:Amino Acid Oxidoreductases / Q000235:genetics / Q000378:metabolism*; D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D003013:Clostridium / Q000201:enzymology*; D003470:Culture Media; D006801:Humans; D008969:Molecular Sequence Data; D009097:Multienzyme Complexes / Q000235:genetics / Q000378:metabolism*; D012643:Selenium / Q000378:metabolism*; D051140:Selenoproteins; D016415:Sequence Alignment; D014208:Treponema / Q000201:enzymology* / Q000254:growth & development*
D001426:Bacterial Proteins; D003470:Culture Media; D009097:Multienzyme Complexes; D051140:Selenoproteins; C097253:selenoprotein B, Bacteria; D000594:Amino Acid Oxidoreductases; C020815:glycine reductase; C097252:glycine reductase complex selenoprotein A, Clostridium; D012643:Selenium