【摘要】 通过原位杂交从巴西固氮螺菌（Ａｚｏｓｐｉｒｉｌｌｕｍ　ｂｒａｓｉｌｅｎｓｅ）Ｙｕ６２的基因组文库中获得ｇｌｎＺ基因的阳性克隆，对该阳性克隆进行亚克隆和序列分析，结果表明 ｇｌｎＺ基因位于 ３．７ ｋｂ的 ＳａＬＩ片段上。ｇｌｎＺ基因编码区长 ３３６ ｂＰ，编码的产物是 Ｐｚ蛋白，由１１２个氨基酸组成，分子量为１．１２ｋＤ。用Ｂｌａｓｔａｘ软件对Ｐｚ蛋白的氨基酸序列在ＧｅｎＢａｎｋ数据库中进行同源比较，结果表明Ｐｚ蛋白与其它几种固氮菌及大肠杆菌的ＧｌｎＫ蛋白的同源性（ｉｄｅｎｔｉｔｉｅｓ）达６６％以上；与ＰⅡ蛋白的同源性达６４％以上。 ｇｌｎＺ基因上游是部分ｕｂｉＨ－ｌｉｋｅ基因，与Ｅ．ｃｏｌｉ　ｕｂｉＨ基因（编码辅酶Ｑ， ｕｂｉｑｕｉｎｏｎｅ） Ｎ－端有３１％的同源性（ｉｄｅｎｔｉｔｙ）和５０％相似性（ｓｉｍｉｌａｒｉｔｙ）；ｇｌｎＺ基因下游是 ａａｔ－ｌｉｋｅ基因，与 Ｅ． ｃｏｌｉ和 Ｂａｃｉｌｌｕｓ ｓｕｂｔｉｌｉｓ ａａｔ基因（编码天冬氨酸氨基转移酶，ａｓｐａｒｔａｔｅ ａｍｉｎｏｔｒａｎｓｆｅｒａｓｅ）有同源性和相似性都为２６％和４２％；ａａｔ－ｌｉｋｅ基因下游是部分ｆｔｓＫ－ｌｉｋｅ基因，与Ｅ．ｃｏｌｉ ｆｔｓＫ?更多还原

【Abstract】 The glnZ gene of A. brasilense was determined in a 3.7 kb SalI fragment, and ubiH-like, aat-like and ftsK-like genes were clustered around glnZ. A partial ubiH-like gene (required for ubiquinone synthesis) precedes glnZ and is transcribed from the opposite strand. The ubiH-like gene of A. brasilense has 31% identitiy and 50% similarity with ubiH gene of E. coli. The aat (aspartate aminotransferase)-like and ftsK (involved in peptidoglycan synthesis during cell septation ) -like genes were found clustered downstream of glnZ. The aat-like gene of A. brasilense has 26% identity and 42% similarity with aat gene of E. coli. The ftsK-like gene of A. brasilense has 42% identity and 56% similarity with ftsK gene of E. coli. The glnZ gene encodes 112 amino acid-long Pz polypeptide, maping between positions 1057~1395bp. The amino acid sequence of Pz from A. brasilense is more than 66% identical to that of GlnK protein from several dizotrophs and E. coli.更多还原