The tus gene of Escherichia coli: autoregulation, analysis of flanking sequences and identification of a complementary system in Salmonella typhimurium.
The tus gene of Escherichia coli encodes a DNA-binding protein that, when bound to terminator sites, blocks replication forks. One of these sites, TerB, is immediately upstream from tus, and we have determined that the 5' end of tus mRNA is in the TerB site, that tus is autoregulated and that pTus is a very low efficiency promoter. Analysis of the DNA upstream from tus and TerB indicates a set of sensor/regulator genes which are comparable to envZ/ompR. Although tus mutants exhibit no growth phenotype in laboratory conditions, Salmonella typhimurium and E. coli have nevertheless maintained similar termination systems. Sequence homology can be demonstrated by Southern hybridizations, and the systems also exhibit functional complementation: the Tus protein of S. typhimurium blocks DNA replication at the TerA site of E. coli.
Roecklein
B
B
Molecular, Cellular and Developmental Biology Department, University of Colorado, Boulder 80309.
Pelletier
A
A
Kuempel
P
P
D001426:Bacterial Proteins / Q000235:genetics; D001483:Base Sequence; D002874:Chromosome Mapping; D004261:DNA Replication / Q000235:genetics; D004269:DNA, Bacterial / Q000235:genetics; D004268:DNA-Binding Proteins / Q000235:genetics; D004926:Escherichia coli / Q000235:genetics*; D029968:Escherichia coli Proteins; D015964:Gene Expression Regulation, Bacterial; D005798:Genes, Bacterial; D005816:Genetic Complementation Test; D008969:Molecular Sequence Data; D012486:Salmonella typhimurium / Q000235:genetics; D012689:Sequence Homology, Nucleic Acid
D001426:Bacterial Proteins; D004269:DNA, Bacterial; D004268:DNA-Binding Proteins; D029968:Escherichia coli Proteins; C061910:tus protein, Bacteria; C489236:tus protein, E coli