Extracytoplasmic prosthetic group ligation to apoproteins: maturation of c-type cytochromes.
In all organisms, haem is post-translationally and covalently attached to c apocytochromes to produce c holocytochromes via a process called c-type cytochromes maturation, which involves numerous components. In bacteria it was not clear which of these components catalyses the extracytoplasmic haem-apocytochrome ligation per se. In this issue of Molecular Microbiology, Feissner and colleagues report that a single polypeptide from Helicobacter pylori, corresponding to the fusion of two proteins found in other organisms, performs haem ligation to a coexpressed Bordetella pertussis apocytochrome c in an Escherichia coli mutant lacking its own cytochrome c maturation proteins. This simple experimental system pinpoints the components catalysing extracytoplasmic covalent haem ligation and raises intriguing issues about the requirements for delivery of haem and apocytochrome c substrates to produce c holocytochromes.
Turkarslan
Serdar
S
University of Pennsylvania, Department of Biology, Plant Science Institute, Philadelphia, PA 19104, USA.
Sanders
Carsten
C
Daldal
Fevzi
F
D001886:Bordetella pertussis / Q000201:enzymology / Q000235:genetics / Q000378:metabolism; D045304:Cytochromes c / Q000235:genetics / Q000378:metabolism*; D003575:Cytochromes c1 / Q000378:metabolism*; D045362:Cytochromes c2 / Q000378:metabolism*; D004926:Escherichia coli / Q000201:enzymology* / Q000235:genetics / Q000378:metabolism; D006418:Heme / Q000378:metabolism; D009154:Mutation; D011994:Recombinant Proteins / Q000378:metabolism*
D011994:Recombinant Proteins; D006418:Heme; D045304:Cytochromes c; D003575:Cytochromes c1; D045362:Cytochromes c2