title: Compact archaeal variant of heme A synthase.
abstract: The N- and C-terminal halves of the heme A synthase polypeptide of Bacillus subtilis, and many other organisms, are homologous. This indicates that these enzyme proteins originate from a tandem duplication and fusion event of a gene encoding a protein half as large. The ape1694 gene of the hyperthermophilic archaeon Aeropyrum pernix encodes a protein that is similar to the hypothetical small primordial protein. We demonstrate that this A. pernix protein is a heat-stable membrane bound heme A synthase designated cCtaA. The case of cCtaA is unusual in evolution in that the primordial-like protein has not become extinct and apparently carries out the same function as the twice as large more diversified heme A synthase protein variant found in most cytochrome a-containing organisms.
authors.affiliation: Department of Cell & Organism Biology, Lund University, Sölvegatan 35, SE 22362 Lund, Sweden. anna.lewin@cob.lu.se
authors.forename: Anna
authors.initials: A
authors.lastname: Lewin
authors.forename: Lars
authors.initials: L
authors.lastname: Hederstedt
mesh_terms: D041522:Aeropyrum / Q000201:enzymology / Q000235:genetics*; D019843:Archaeal Proteins / Q000235:genetics* / Q000378:metabolism; D001412:Bacillus subtilis / Q000201:enzymology / Q000235:genetics*; D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism; D003573:Cytochrome b Group / Q000235:genetics*; D019143:Evolution, Molecular; D020440:Gene Duplication; D006418:Heme / Q000031:analogs & derivatives / Q000096:biosynthesis / Q000235:genetics; D008565:Membrane Proteins / Q000235:genetics* / Q000378:metabolism
chemical_list: D019843:Archaeal Proteins; D001426:Bacterial Proteins; C090098:CtaA protein, bacteria; D003573:Cytochrome b Group; D008565:Membrane Proteins; C027728:heme a; D006418:Heme