LOCALIZATION OF THE SEQUENCE-DETERMINED DNA BENDING CENTER UPSTREAM OF THE STREPTOKINASE GENE SKC

DNA sequences upstream of the core promoter region of the streptokinas e gene (skc) from Streptococcus equisimilis H46A increase skc transcri ption more than tenfold in vivo. This promoter upstream region contain s a segment of intrinsically bent DNA, the precise location of which w as determined experimentally by circular permutation analysis and theo retically by computer prediction. Electrophoretic analysis of circular ly permuted upstream DNA fragments placed the bend center approximatel y at position-100 with respect to the major transcription initiation s ite of skc. This position was in excellent agreement with the center o f maximum curvature predicted theoretically. Knowledge of the precise location of the bend center will be useful for future studies of the p ossible effect of DNA bending on skc transcription.