title: The YedZ family: possible heme binding proteins that can be fused to transporters and electron carriers.
abstract: YedZ of Escherichia coli is an integral 6 transmembrane spanning (TMS) protein of unknown function. We have identified homologues of YedZ in bacteria and animals but could not find homologues in Archaea or the other eukaryotic kingdoms. YedZ homologues exhibit conserved histidyl residues in their transmembrane domains that may function in heme binding. Some of the homologues encoded in the genomes of magnetotactic bacteria and cyanobacteria have YedZ domains fused to transport and electron transfer proteins, respectively. One of the animal homologues is the 6 TMS epithelial plasma membrane antigen of the prostate (STAMP1) that is overexpressed in prostate cancer. Animal homologues have YedZ domains fused C-terminal to homologues of coenzyme F420-dependent NADP oxidoreductases. YedZ homologues are shown to have arisen by intragenic triplication of a 2 TMS-encoding element. They exhibit slight but statistically significant sequence similarity to two families of putative heme export systems and one family of cytochrome-containing electron carriers. We propose that YedZ homologues function as heme-binding proteins that can facilitate or regulate oxidoreduction, transmembrane electron flow and transport.
authors.affiliation: Division of Biological Sciences, University of California at San Diego, La Jolla, CA 92093-0116, USA.
authors.forename: Torsten
authors.initials: T
authors.lastname: von Rozycki
authors.forename: Ming-Ren
authors.initials: MR
authors.lastname: Yen
authors.forename: Erik E
authors.initials: EE
authors.lastname: Lende
authors.forename: Milton H
authors.initials: MH
authors.lastname: Saier
mesh_terms: D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D000818:Animals; D002352:Carrier Proteins / Q000235:genetics; D019295:Computational Biology; D017124:Conserved Sequence; D004579:Electron Transport; D029968:Escherichia coli Proteins / Q000737:chemistry / Q000235:genetics*; D019143:Evolution, Molecular; D000081062:Heme-Binding Proteins; D006420:Hemeproteins / Q000235:genetics; D006801:Humans; D008565:Membrane Proteins / Q000235:genetics; D026901:Membrane Transport Proteins / Q000737:chemistry / Q000235:genetics*; D008969:Molecular Sequence Data; D009363:Neoplasm Proteins / Q000235:genetics; D010088:Oxidoreductases; D010802:Phylogeny; D017386:Sequence Homology, Amino Acid
chemical_list: D002352:Carrier Proteins; D029968:Escherichia coli Proteins; D000081062:Heme-Binding Proteins; D006420:Hemeproteins; D008565:Membrane Proteins; D026901:Membrane Transport Proteins; D009363:Neoplasm Proteins; D010088:Oxidoreductases; C467741:STEAP2 protein, human