title: RcoM: a new single-component transcriptional regulator of CO metabolism in bacteria.
abstract: Genomic analysis suggested the existence of a CO-sensing bacterial transcriptional regulator that couples an N-terminal PAS fold domain to a C-terminal DNA-binding LytTR domain. UV/visible-light spectral analyses of heterologously expressed, purified full-length proteins indicated that they contained a hexacoordinated b-type heme moiety that avidly binds CO and NO. Studies of protein variants strongly suggested that the PAS domain residues His74 and Met104 serve as the heme Fe(II) axial ligands, with displacement of Met104 upon binding of the gaseous effectors. Two RcoM (regulator of CO metabolism) homologs were shown to function in vivo as CO sensors capable of regulating an aerobic CO oxidation (cox) regulon. The genetic linkage of rcoM with both aerobic (cox) and anaerobic (coo) CO oxidation systems suggests that in different organisms RcoM proteins may control either regulon type.
authors.affiliation: Department of Bacteriology, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA.
authors.forename: Robert L
authors.initials: RL
authors.lastname: Kerby
authors.forename: Hwan
authors.initials: H
authors.lastname: Youn
authors.forename: Gary P
authors.initials: GP
authors.lastname: Roberts
mesh_terms: D000332:Aerobiosis / Q000235:genetics; D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D019117:Burkholderia / Q000235:genetics / Q000378:metabolism; D002248:Carbon Monoxide / Q000378:metabolism*; D004926:Escherichia coli / Q000235:genetics; D015964:Gene Expression Regulation, Bacterial; D016680:Genome, Bacterial; D023281:Genomics; D006418:Heme / Q000378:metabolism; D008024:Ligands; D008969:Molecular Sequence Data; D009569:Nitric Oxide / Q000378:metabolism; D010084:Oxidation-Reduction; D010100:Oxygen / Q000378:metabolism; D017434:Protein Structure, Tertiary / Q000235:genetics; D018085:Regulon; D014157:Transcription Factors / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*
chemical_list: D001426:Bacterial Proteins; D008024:Ligands; D014157:Transcription Factors; D009569:Nitric Oxide; D006418:Heme; D002248:Carbon Monoxide; D010100:Oxygen