title: C-type cytochromes: diverse structures and biogenesis systems pose evolutionary problems.
abstract: C-type cytochromes are a structurally diverse group of haemoproteins, which are related by the occurrence of haem covalently attached to a polypeptide via two thioether bonds formed by the vinyl groups of haem and cysteine side chains in a CXXCH peptide motif. Remarkably, three different post-translational systems for forming these cytochromes have been identified. The evolution of both the proteins themselves and the biogenesis systems poses many questions to which answers are currently being sought. In this article we review the progress that has been made in understanding the need for covalent attachment of haem to proteins in cytochromes c and the complex systems involved in their formation.
authors.affiliation: Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, UK.
authors.forename: James W A
authors.initials: JW
authors.lastname: Allen
authors.forename: Oliver
authors.initials: O
authors.lastname: Daltrop
authors.forename: Julie M
authors.initials: JM
authors.lastname: Stevens
authors.forename: Stuart J
authors.initials: SJ
authors.lastname: Ferguson
mesh_terms: D020816:Amino Acid Motifs; D003574:Cytochrome c Group / Q000737:chemistry* / Q000378:metabolism*; D019143:Evolution, Molecular; D000069497:Origin of Life; D011487:Protein Conformation; D011499:Protein Processing, Post-Translational
chemical_list: D003574:Cytochrome c Group