Sequence-directed DNA bending upstream of the streptokinase promoter.
A 450-base pair (bp) HinfI restriction fragment from the chromosome of Streptococcus equisimilis H46A contains the early coding region of the streptokinase gene (skc), the skc promoter, and a stretch of DNA 5' to the--35 region of the skc promoter. Two-dimensional polyacrylamide (PA) gel electrophoresis at two different temperatures showed that this fragment migrates anomalously slowly on PA gels, suggesting the existence of a bent DNA conformation. Inspection of the nucleotide sequence confirmed this suggestion by revealing numerous oligomeric dA.dT tracts, some of which are in phase with the helix screw. Computer analysis of the sequence predicted the existence of two bending loci, one of which is located upstream of the skc promoter. In addition to showing DNA bending, the 450-bp HinfI fragment contains multiple 13-bp sequences homologous to the Escherichia coli integration host factor DNA-binding consensus sequence. Insertion of IS1 into a site immediately upstream of the--35 region decreased the expression level of skc in E. coli, suggesting that DNA conformation upstream of the promoter has a role in skc expression.
Müller
J
J
Akademie der Wissenschaften der DDR.
Malke
H
H
D001483:Base Sequence; D004269:DNA, Bacterial / Q000032:analysis*; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D011401:Promoter Regions, Genetic; D013300:Streptokinase / Q000235:genetics*
D004269:DNA, Bacterial; D013300:Streptokinase