Long-range interaction between two promoters: activation of the leu-500 promoter by a distant upstream promoter.
The leu-500 mutation can be suppressed in S. typhimurium topA. Previous studies have demonstrated that the plasmid-borne leu-500 minimal promoter cannot be activated in topA mutants unless adjacent (< 250 bp) transcription occurs away from the leu-500 promoter (short-range promoter interaction). To search for a potential upstream promoter responsible for activation of leu-500 in the chromosomal context, we have identified the ilvlH promoter, located 1.9 kb upstream of leu-500 (long-range promoter interaction). Different from short-range promoter interaction, which is abolished by DNA sequence insertions, the long-range promoter interaction is mediated by the intervening DNA sequence. These studies suggest that the long-range interaction between a pair of divergently arrayed promoters is probably mediated by a complex process involving relay of DNA supercoiling by the DNA sequence located between the two promoters.
Wu
H Y
HY
Department of Pharmacology, School of Medicine, Wayne State University, Detroit, Michigan 48201, USA.
Tan
J
J
Fang
M
M
D001483:Base Sequence; D004269:DNA, Bacterial / Q000235:genetics*; D015964:Gene Expression Regulation, Bacterial; D008969:Molecular Sequence Data; D010957:Plasmids / Q000235:genetics; D011401:Promoter Regions, Genetic / Q000235:genetics*; D012486:Salmonella typhimurium / Q000235:genetics*
D004269:DNA, Bacterial