根癌土壤杆菌C58氮调节基因ntrC的鉴定、克隆及序列分析。

Identification, cloning, and sequence analysis of the nitrogen regulation gene ntrC of Agrobacterium tumefaciens C58.

作者信息

Wardhan H, McPherson M J, Sastry G R

机构信息

Department of Genetics, University of Leeds, U.K.

出版信息

Mol Plant Microbe Interact. 1989 Sep-Oct;2(5):241-8. doi: 10.1094/mpmi-2-241.

DOI:10.1094/mpmi-2-241

PMID:2520824

Abstract

We describe the cloning of an ntrC gene of Agrobacterium tumefaciens C58 by interspecific complementation of an Escherichia coli ntrC mutant. Restriction mapping and Southern blot analysis of the complementing clone identified a 1.7-kb EcoRI-PvuII DNA fragment whose sequence was determined. Analysis of this sequence revealed coding regions corresponding to a complete ntrC gene and the C-terminal region of an ntrB gene. Amino acid sequence comparisons of A. tumefaciens NTRC protein with NTRC sequences from Rhizobium meliloti, Bradyrhizobium sp. (Parasponia), Klebsiella pneumoniae, E. coli, and Salmonella typhimurium show strong sequence conservation supporting DNA hybridization data, demonstrating strong evolutionary homology among ntrC genes of Rhizobiaceae. The C58 NTRC protein has been identified, by 35S-labeling, in a T7 RNA polymerase (pT7-7) expression vector system.

摘要

我们通过大肠杆菌ntrC突变体的种间互补描述了根癌土壤杆菌C58的ntrC基因的克隆。对互补克隆进行限制性图谱分析和Southern印迹分析，鉴定出一个1.7 kb的EcoRI - PvuII DNA片段，并测定了其序列。对该序列的分析揭示了对应于完整ntrC基因和ntrB基因C末端区域的编码区。根癌土壤杆菌NTRC蛋白与苜蓿根瘤菌、慢生根瘤菌属（Parasponia）、肺炎克雷伯菌、大肠杆菌和鼠伤寒沙门氏菌的NTRC序列的氨基酸序列比较显示出强烈的序列保守性，支持DNA杂交数据，证明了根瘤菌科ntrC基因之间存在强烈的进化同源性。通过35S标记，在T7 RNA聚合酶（pT7 - 7）表达载体系统中鉴定出了C58 NTRC蛋白。