Identification of a bacterial di-haem cytochrome c peroxidase from Methylomicrobium album BG8.
The nucleotide sequence of an open reading frame (corB) downstream of the copper-repressible CorA-encoding gene of the methanotrophic bacterium Methylomicrobium album BG8 was obtained by restriction enzyme digestion and inverse PCR. The amino acid sequence deduced from this gene showed significant sequence similarity to the surface-associated di-haem cytochrome c peroxidase (SACCP) previously isolated from Methylococcus capsulatus (Bath), including both c-type haem-binding motifs. Homology analysis placed this protein, phylogenetically, within the subfamily containing the M. capsulatus SACCP of the bacterial di-haem cytochrome c peroxidase (BCCP) family of proteins. Immunospecific recognition confirmed synthesis of the M. album CorB as a protein non-covalently associated with the outer membrane and exposed to the periplasm. corB expression is regulated by the availability of copper ions during growth and the protein is most abundant in M. album when grown at a low copper-to-biomass ratio, indicating an important physiological role of CorB under these growth conditions. corB was co-transcribed with the gene encoding CorA, constituting a copper-responding operon, which appears to be under the control of a sigma(54)-dependent promoter. M. album CorB is the second isolated member of the recently described subfamily of the BCCP family of proteins. So far, these proteins have only been described in methanotrophic bacteria.
Karlsen
O A
OA
Department of Molecular Biology, University of Bergen, Thormøhlensgate 55, N-5020 Bergen, Norway.
Larsen
Ø
Ø
Department of Molecular Biology, University of Bergen, Thormøhlensgate 55, N-5020 Bergen, Norway.
Jensen
H B
HB
Department of Molecular Biology, University of Bergen, Thormøhlensgate 55, N-5020 Bergen, Norway.
D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D001483:Base Sequence; D003001:Cloning, Molecular; D003578:Cytochrome-c Peroxidase / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D006418:Heme / Q000378:metabolism*; D008772:Methylococcaceae / Q000737:chemistry / Q000201:enzymology* / Q000235:genetics; D020619:Methylococcus capsulatus; D008969:Molecular Sequence Data; D009876:Operon; D021381:Protein Transport; D016415:Sequence Alignment
D001426:Bacterial Proteins; D006418:Heme; D003578:Cytochrome-c Peroxidase