Lovett C M, Love P E, Yasbin R E
Department of Chemistry, Williams College, Williamstown, Massachusetts 01267.
J Bacteriol. 1989 May;171(5):2318-22. doi: 10.1128/jb.171.5.2318-2322.1989.
The development of competence in Bacillus subtilis is accompanied by the transcriptional activation of DNA damage-inducible (din) operons and other SOS-like responses. We report here that B. subtilis Rec protein (the analog of Escherichia coli RecA), a DNA damage-inducible protein, is substantially induced when cells differentiate to a state of competence. We quantitated the induction of B. subtilis Rec protein and the B. subtilis din-22 operon (representative of all known B. subtilis din operons) during competence development in Rec+ and DNA repair-deficient strains. We present two lines of evidence that Rec protein induction in competent cells is controlled by a competence-specific mechanism that is distinct from the SOS-like regulation that controls Rec induction following DNA damage: (i) Rec protein was significantly induced in rec mutants (recA1 and recE4) that are highly deficient in Rec induction by DNA damage, and (ii) Rec protein induction during competence development was greater than maximum Rec induction by DNA damage. On the other hand, our results suggest that the din-22 operon is induced by the same (SOS-like) mechanism both during competence development and after DNA damage.
枯草芽孢杆菌感受态的发育伴随着DNA损伤诱导型（din）操纵子的转录激活和其他类似SOS的反应。我们在此报告，枯草芽孢杆菌Rec蛋白（大肠杆菌RecA的类似物），一种DNA损伤诱导型蛋白，在细胞分化为感受态时会大量诱导产生。我们对Rec+和DNA修复缺陷型菌株在感受态发育过程中枯草芽孢杆菌Rec蛋白和枯草芽孢杆菌din - 22操纵子（代表所有已知的枯草芽孢杆菌din操纵子）的诱导情况进行了定量分析。我们提供了两条证据表明，感受态细胞中Rec蛋白的诱导是由一种感受态特异性机制控制的，该机制不同于控制DNA损伤后Rec诱导的类似SOS的调控：（i）在rec突变体（recA1和recE4）中Rec蛋白显著诱导，这些突变体在DNA损伤诱导Rec方面高度缺陷；（ii）感受态发育过程中Rec蛋白的诱导大于DNA损伤时Rec诱导的最大值。另一方面，我们的结果表明，din - 22操纵子在感受态发育期间和DNA损伤后都是由相同的（类似SOS的）机制诱导的。
