title: Sequence, transcriptional analysis and chromosomal location of the Xanthomonas campestris pv. campestris uvrB gene.
abstract: The uvrB gene of Xanthomonas campestris pv. campestris, a Gram-negative plant pathogenic bacterium inhabiting soil and infected plants, was cloned and sequenced. This gene has the capacity to encode a polypeptide of 673 amino acid residues with a calculated molecular mass of 75.9 kDa. Its deduced amino acid sequence shows a high degree of similarity and possesses domain conservation to those of bacterial UvrB. The uvrB mutant, isolated by gene replacement, is extremely sensitive to ultraviolet irradiation. Like the situation in the X. campestris pv. campestris recA gene, no SOS box is present upstream of the uvrB gene. Northern blotting and transcriptional fusion assay with lacZ indicated that X. campestris pv. campestris uvrB is expressed constitutively at high levels and cannot be further induced by UV irradiation. These results suggest a regulatory mechanism different from that for the expression of Escherichia coli uvrB. Using a gene-tagging strategy in conjunction with pulsed-field gel electrophoresis, the uvrB gene was located near 1 o'clock on the X. campestris pv. campestris 17 chromosome (4.8 Mb) map, which is far apart from the lexA-recA-recX cluster near 5 o'clock.
authors.affiliation: Institute of Molecular Biology, National Chung Hsing University, Taichung, Taiwan, Republic of China.
authors.forename: T C
authors.initials: TC
authors.lastname: Lee
authors.forename: M C
authors.initials: MC
authors.lastname: Lee
authors.forename: C H
authors.initials: CH
authors.lastname: Hung
authors.forename: S F
authors.initials: SF
authors.lastname: Weng
authors.forename: Y H
authors.initials: YH
authors.lastname: Tseng
mesh_terms: D000595:Amino Acid Sequence; D001483:Base Sequence; D002874:Chromosome Mapping; D017124:Conserved Sequence; D004265:DNA Helicases / Q000235:genetics*; D004269:DNA, Bacterial / Q000235:genetics; D029968:Escherichia coli Proteins; D008969:Molecular Sequence Data; D009154:Mutation; D011836:Radiation Tolerance / Q000235:genetics; D014158:Transcription, Genetic; D014466:Ultraviolet Rays; D016959:Xanthomonas campestris / Q000235:genetics* / Q000472:pathogenicity / Q000528:radiation effects
chemical_list: D004269:DNA, Bacterial; D029968:Escherichia coli Proteins; C058093:UvrB protein, E coli; D004265:DNA Helicases