Clarke P, Lee J H, Burke K, Wilcox G
Department of Microbiology, University of California, Los Angeles 90024.
Gene. 1992 Aug 1;117(1):31-7. doi: 10.1016/0378-1119(92)90486-9.
The araC gene encodes a regulatory protein, AraC, that acts as both an activator and a repressor of transcription of the genes involved in the transport and catabolism of L-arabinose in Salmonella typhimurium LT2. Five araC mutants which have altered regulatory properties were characterized. All are point mutations which would result in amino acid substitutions near the C terminus of AraC. Each mutation results in altered activator and auto-regulatory AraC function in vivo. In vitro DNA-binding assays showed that three mutant AraC have measurable lowered affinity for ara controlling site DNA. The data are consistent with a model in which there is a DNA-binding domain in the C terminus of AraC which functions in both activation and repression.
araC基因编码一种调节蛋白AraC，它在鼠伤寒沙门氏菌LT2中作为L-阿拉伯糖转运和分解代谢相关基因转录的激活剂和阻遏物。对五个具有改变调节特性的araC突变体进行了表征。所有这些都是点突变，会导致AraC C末端附近的氨基酸替换。每个突变都会导致体内激活剂和自调节AraC功能发生改变。体外DNA结合试验表明，三种突变型AraC对ara控制位点DNA的亲和力可测量地降低。这些数据与一个模型一致，即AraC的C末端存在一个DNA结合结构域，其在激活和阻遏中均起作用。
