title: Chromosomal location of the Escherichia coli cytochrome b556 gene, cybA.
abstract: The amounts of cytochrome b556 in the cytoplasmic membranes of several Escherichia coli K12 strains having F-prime factors and a lambda transducing phage were determined. The amount was amplified about two-fold in strains having F100-12 and F152, but not in strains having F100-11, F8 and lambda psu+2glnS+. The strain TK3D11, which lacks the kdp-gltA region (deletion D-01) of the E. coli chromosome, did not synthesize cytochrome b556 at all. From these results, the gene cybA encoding cytochrome b556 was located in the kdp-gltA region. In the cytochrome b556-deficient mutant, a novel b type cytochrome, cytochrome b561 which is a product of the gene cybB, was identified. It seems to function as a physiological electron transferring cytochrome in place of cytochrome b556 in this mutant.
mesh_terms: D010582:Bacteriophage lambda / Q000235:genetics; D002874:Chromosome Mapping; D002876:Chromosomes, Bacterial / Q000648:ultrastructure; D003573:Cytochrome b Group / Q000235:genetics*; D004926:Escherichia coli / Q000235:genetics*; D005144:F Factor; D005784:Gene Amplification; D005798:Genes, Bacterial
chemical_list: D003573:Cytochrome b Group; C023646:cytochrome b561; C018256:cytochrome b556