Modification of heme c binding motifs in the small subunit (NrfH) of the Wolinella succinogenes cytochrome c nitrite reductase complex.
The two multiheme c-type cytochromes NrfH and NrfA form a membrane-bound complex that catalyzes menaquinol oxidation by nitrite during respiratory nitrite ammonification of Wolinella succinogenes. Each cysteine residue of the four NrfH heme c binding motifs was individually replaced by serine. Of the resulting eight W. succinogenes mutants, only one is able to grow by nitrite respiration although its electron transport activity from formate to nitrite is decreased. NrfH from this mutant was shown by matrix-assisted laser desorption/ionization mass spectrometry to carry four covalently bound heme groups like wild-type NrfH indicating that the cytochrome c biogenesis system II organism W. succinogenes is able to attach heme to an SXXCH motif.
Simon
Jörg
J
Institut für Mikrobiologie, Johann Wolfgang Goethe-Universität, Marie-Curie-Str. 9, D-60439 Frankfurt am Main, Germany. j.simon@em.uni-frankfurt.de
Eichler
Robert
R
Pisa
René
R
Biel
Simone
S
Gross
Roland
R
D020816:Amino Acid Motifs; D001426:Bacterial Proteins / Q000378:metabolism; D001665:Binding Sites; D003470:Culture Media; D003545:Cysteine / Q000235:genetics / Q000378:metabolism; D003574:Cytochrome c Group / Q000378:metabolism*; D045263:Cytochromes a1; D003575:Cytochromes c1; D006418:Heme / Q000031:analogs & derivatives* / Q000378:metabolism*; D016297:Mutagenesis, Site-Directed; D009565:Nitrate Reductases / Q000235:genetics / Q000378:metabolism*; D009573:Nitrites / Q000378:metabolism; D010084:Oxidation-Reduction; D016601:RNA-Binding Proteins; D012694:Serine / Q000235:genetics / Q000378:metabolism; D014157:Transcription Factors / Q000378:metabolism; D016968:Wolinella / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*
D001426:Bacterial Proteins; D003470:Culture Media; D003574:Cytochrome c Group; D009573:Nitrites; D016601:RNA-Binding Proteins; D014157:Transcription Factors; C087372:nfrA protein, Azorhizobium caulinodans; C031690:heme C; D006418:Heme; D012694:Serine; D045263:Cytochromes a1; D003575:Cytochromes c1; D009565:Nitrate Reductases; C054690:nitrate reductase (cytochrome); D003545:Cysteine