title: What is the substrate specificity of the System I cytochrome c biogenesis apparatus?
abstract: c-Type cytochromes are characterized by covalent attachment of haem to protein through thioether bonds between the vinyl groups of the haem and the thiols of a CXXCH motif. Proteins of this type play crucial roles in the biochemistry of the nitrogen cycle. Many Gram-negative bacteria use the Ccm (cytochrome c maturation) proteins for the post-translational haem attachment to their c-type cytochromes; in the present paper, we discuss the substrate specificity of the Ccm apparatus. The main conclusion is that the feature recognized and required in the apocytochrome is simply the two cysteines and the histidine of the haem-binding motif.
authors.affiliation: Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, UK. james.allen@bioch.ox.ac.uk
authors.forename: J W A
authors.initials: JW
authors.lastname: Allen
authors.forename: S J
authors.initials: SJ
authors.lastname: Ferguson
mesh_terms: D020816:Amino Acid Motifs; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D003574:Cytochrome c Group / Q000096:biosynthesis*; D006418:Heme / Q000378:metabolism; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D013379:Substrate Specificity
chemical_list: D001426:Bacterial Proteins; D003574:Cytochrome c Group; D008565:Membrane Proteins; D006418:Heme