Overproduction of three genes leads to camphor resistance and chromosome condensation in Escherichia coli.
We isolated and characterized three genes, crcA, cspE and crcB, which when present in high copy confer camphor resistance on a cell and suppress mutations in the chromosomal partition gene mukB. Both phenotypes require the same genes. Unlike chromosomal camphor resistant mutants, high copy number crcA, cspE and crcB do not result in an increase in the ploidy of the cells. The cspE gene has been previously identified as a cold shock-like protein with homologues in all organisms tested. We also demonstrate that camphor causes the nucleoids to decondense in vivo and when the three genes are present in high copy, the chromosomes do not decondense. Our results implicate camphor and mukB mutations as interfering with chromosome condensation and high copy crcA, cspE and crcB as promoting or protecting chromosome folding.
Hu
K H
KH
Laboratory of Molecular Biology, National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892, USA.
Liu
E
E
Dean
K
K
Gingras
M
M
DeGraff
W
W
Trun
N J
NJ
D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000235:genetics; D001483:Base Sequence; D002164:Camphor / Q000494:pharmacology*; D002868:Chromosomal Proteins, Non-Histone; D002874:Chromosome Mapping; D002876:Chromosomes, Bacterial / Q000187:drug effects / Q000235:genetics / Q000648:ultrastructure*; D003001:Cloning, Molecular; D004251:DNA Transposable Elements / Q000235:genetics; D004269:DNA, Bacterial / Q000235:genetics; D004352:Drug Resistance, Microbial / Q000235:genetics; D004926:Escherichia coli / Q000187:drug effects* / Q000235:genetics* / Q000648:ultrastructure; D029968:Escherichia coli Proteins; D005784:Gene Amplification; D005798:Genes, Bacterial; D006360:Heat-Shock Proteins / Q000235:genetics; D008969:Molecular Sequence Data; D009154:Mutation; D010641:Phenotype; D010957:Plasmids / Q000235:genetics; D017386:Sequence Homology, Amino Acid
D001426:Bacterial Proteins; D002868:Chromosomal Proteins, Non-Histone; C088097:CspE protein, E coli; D004251:DNA Transposable Elements; D004269:DNA, Bacterial; D029968:Escherichia coli Proteins; D006360:Heat-Shock Proteins; C067035:MukB protein, E coli; D002164:Camphor