Oskouian B, Stewart G C
Department of Microbiology, University of Kansas, Lawrence 66045.
J Bacteriol. 1990 Jul;172(7):3804-12. doi: 10.1128/jb.172.7.3804-3812.1990.
The lacR gene encodes the repressor of the lactose operon of S. aureus. The nucleotide sequence of this gene and the promoter-operator region of the operon are reported. The lacR gene encodes a protein with a molecular weight of 28,534. This protein was found to share sequence homology with the DeoR protein, the repressor of the E. coli deoxyribonucleotide operon. Directly and invertedly repeated sequences were found associated with the promoter for the structural genes of the operon. These sequences were examined by site-directed mutagenesis and found to be important in repressor binding and in the binding of a catabolite repressor. Evidence is presented in support of a model for catabolite repression of the operon which involves a negative-acting transcriptional regulator which binds to the promoter region of the operon and prevents transcription.
lacR基因编码金黄色葡萄球菌乳糖操纵子的阻遏物。本文报道了该基因的核苷酸序列以及操纵子的启动子-操纵基因区域。lacR基因编码一种分子量为28,534的蛋白质。发现该蛋白质与大肠杆菌脱氧核糖核苷酸操纵子的阻遏物DeoR蛋白具有序列同源性。发现与操纵子结构基因的启动子相关的正向和反向重复序列。通过定点诱变对这些序列进行了研究，发现它们在阻遏物结合和分解代谢物阻遏物的结合中很重要。本文提供的证据支持了一种操纵子分解代谢物阻遏模型，该模型涉及一种负向作用的转录调节因子，它与操纵子的启动子区域结合并阻止转录。
