title: radC102 of Escherichia coli is an allele of recG.
abstract: The radC102 mutation causes mild UV and X-ray sensitivity and was mapped previously to near pyrE and recG at 82 min on the Escherichia coli chromosome (I. Felzenszwalb, N. J. Sargentini, and K. C. Smith, Radiat. Res. 97:615-625, 1984). We report that radC102 has two striking phenotypes characteristic of recG mutations. First, it causes dramatically increased RecA-dependent mutation in a stationary-phase mutation assay. Second, it causes extreme UV sensitivity in combination with ruv mutations affecting the RuvABC Holliday junction resolution system. DNA sequencing of the radC and recG genes in radC102 strains revealed that the radC102 mutation creates a stop codon in recG that is predicted to truncate the RecG protein at 410 of 603 amino acids. A low-copy-number plasmid carrying the radC(+) gene did not affect the UV sensitivity of a wild-type strain, a radC102 strain, or a recG258::Tn10mini-kan strain. We conclude that radC102 is an allele of recG and that the function of the RadC protein remains to be determined.
authors.affiliation: Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas 77030, USA. lombardo@bcm.tmc.edu
authors.forename: M J
authors.initials: MJ
authors.lastname: Lombardo
authors.forename: S M
authors.initials: SM
authors.lastname: Rosenberg
mesh_terms: D000483:Alleles; D001426:Bacterial Proteins / Q000235:genetics*; D004268:DNA-Binding Proteins; D004926:Escherichia coli / Q000737:chemistry / Q000235:genetics*; D029968:Escherichia coli Proteins; D009154:Mutation
chemical_list: D001426:Bacterial Proteins; D004268:DNA-Binding Proteins; D029968:Escherichia coli Proteins; C074495:yicR protein, E coli; C071446:RecG protein, E coli