Inouye S, Nakazawa A, Nakazawa T
Department of Biochemistry, Yamaguchi University School of Medicine, Ube, Japan.
Gene. 1988 Jun 30;66(2):301-6. doi: 10.1016/0378-1119(88)90366-6.
We have determined the nucleotide sequence of the xylR gene for a transcriptional activator for the degradative pathway of aromatic hydrocarbons on the TOL plasmid from Pseudomonas putida. The 1698-bp sequence for a 566-amino acid (aa) protein (Mr 63741) was identified as the XylR-encoding sequence. Three regions in XylR show homology to Klebsiella pneumoniae NtrC and NifA, both of which are transcriptional activators for the ntr and nif genes involved in the nitrogen metabolism. The central region of XylR (aa 234-473) corresponds to the region that was proposed to interact with RNA polymerase having a sigma factor, NtrA [Drummond et al., EMBO J. 5 (1986) 441-447]. The C-terminal region (aa 515-558) has a putative DNA-binding structure. A short segment proximal to the central region (aa 211-229) is thought to be an interdomain linker. No amino acid homology was found in the N-terminal regions among these proteins. These findings suggest the interaction of XylR with an NtrA in the transcriptional activation of the degradative pathway.
我们已经确定了恶臭假单胞菌TOL质粒上芳烃降解途径转录激活因子xylR基因的核苷酸序列。编码一个566个氨基酸（aa）蛋白质（Mr 63741）的1698 bp序列被鉴定为XylR编码序列。XylR中的三个区域与肺炎克雷伯菌NtrC和NifA具有同源性，这两者都是参与氮代谢的ntr和nif基因的转录激活因子。XylR的中央区域（aa 234 - 473）对应于被认为与具有σ因子NtrA的RNA聚合酶相互作用的区域[Drummond等人，《欧洲分子生物学组织杂志》5（1986）441 - 447]。C端区域（aa 515 - 558）具有推定的DNA结合结构。中央区域近端的一个短片段（aa 211 - 229）被认为是一个结构域间连接子。在这些蛋白质的N端区域未发现氨基酸同源性。这些发现表明XylR在降解途径的转录激活中与NtrA相互作用。
