Insight into the haem d1 biosynthesis pathway in heliobacteria through bioinformatics analysis.
Haem d(1) is a unique tetrapyrrole molecule that serves as a prosthetic group of cytochrome cd(1), which reduces nitrite to nitric oxide during the process of denitrification. Very little information is available regarding the biosynthesis of haem d(1). The extreme difficulty in studying the haem d(1) biosynthetic pathway can be partly attributed to the lack of a theoretical basis for experimental investigation. We report here a gene cluster encoding enzymes involved in the biosynthesis of haem d(1) in two heliobacterial species, Heliobacillus mobilis and Heliophilum fasciatum. The gene organization of the cluster is conserved between the two species, and contains a complete set of genes that lead to the biosynthesis of uroporphyrinogen III and genes thought to be involved in the late steps of haem d(1) biosynthesis. Detailed bioinformatics analysis of some of the proteins encoded in the gene cluster revealed important clues to the precise biochemical roles of the proteins in the biosynthesis of haem d(1), as well as the membrane transport and insertion of haem d(1) into an apocytochrome during the maturation of cytochrome cd(1).
Xiong
Jin
J
Department of Biology, Texas A&M University, College Station, TX 77843, USA.
Bauer
Carl E
CE
Department of Biology, Indiana University, Bloomington, IN 47405, USA.
Pancholy
Anjly
A
Department of Biology, Texas A&M University, College Station, TX 77843, USA.
D000595:Amino Acid Sequence; D001419:Bacteria / Q000235:genetics* / Q000378:metabolism*; D053898:Biosynthetic Pathways; D019295:Computational Biology; D017124:Conserved Sequence; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics*; D023061:Gene Order; D006418:Heme / Q000096:biosynthesis / Q000737:chemistry / Q000235:genetics*; D008958:Models, Molecular; D008969:Molecular Sequence Data; D005810:Multigene Family; D010802:Phylogeny; D017434:Protein Structure, Tertiary; D017422:Sequence Analysis, DNA
D004269:DNA, Bacterial; D006418:Heme