Slack F J, Serror P, Joyce E, Sonenshein A L
Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, Massachusetts 02111, USA.
Mol Microbiol. 1995 Feb;15(4):689-702. doi: 10.1111/j.1365-2958.1995.tb02378.x.
An insertion mutation was isolated that resulted in derepressed expression of the Bacillus subtillis dipeptide transport operon (dpp) during the exponential growth phase in rich medium. DNA flanking the site of insertion was found to encode an operon (codVWXY) of four potential open reading frames (ORFs). The deduced product of the codV ORF is similar to members of the lambda Int family; CodW and CodX are homologous to HsIV and HsIU, two putative heat-shock proteins from Escherichia coli, and to LapC and LapA, two gene products of unknown function from Pasteurella haemolytica. CodX also shares homology with a family of ATPases, including ClpX, a regulatory subunit of the E. coli ClpP protease. CodY does not have any homologues in the data-bases. The insertion mutation and all previously isolated spontaneous cod mutations were found to map in codY. In-frame deletion mutations in each of the other cod genes revealed that only codY is required for repression of dpp in nutrient-rich medium. The codY mutations partially relieved amino acid repression of the histidine utilization (hut) operon but had no effect on regulation of certain other early stationary phase-induced genes, such as spoVG and gsiA.
分离到一种插入突变，该突变导致枯草芽孢杆菌二肽转运操纵子（dpp）在丰富培养基的指数生长期表达去阻遏。发现插入位点两侧的DNA编码一个由四个潜在开放阅读框（ORF）组成的操纵子（codVWXY）。codV ORF的推导产物与λ Int家族成员相似；CodW和CodX与来自大肠杆菌的两种假定热休克蛋白HsIV和HsIU同源，也与溶血巴斯德氏菌中两个功能未知的基因产物LapC和LapA同源。CodX还与包括ClpX（大肠杆菌ClpP蛋白酶的调节亚基）在内的ATP酶家族具有同源性。CodY在数据库中没有任何同源物。发现该插入突变和所有先前分离的自发cod突变都定位在codY中。其他每个cod基因的框内缺失突变表明，在营养丰富的培养基中，只有codY是dpp阻遏所必需的。codY突变部分缓解了组氨酸利用（hut）操纵子的氨基酸阻遏，但对某些其他早期稳定期诱导基因（如spoVG和gsiA）的调控没有影响。
