豆科根瘤菌菜豆生物变种的谷氨酰胺合成酶III编码基因glnT。

The Rhizobium leguminosarum biovar phaseoli glnT gene, encoding glutamine synthetase III.

作者信息

Chiurazzi M, Meza R, Lara M, Lahm A, Defez R, Iaccarino M, Espín G

机构信息

Istituto Internazionale di Genetica e Biofisica, CNR, Napoli, Italy.

出版信息

Gene. 1992 Sep 21;119(1):1-8. doi: 10.1016/0378-1119(92)90060-3.

DOI:10.1016/0378-1119(92)90060-3

PMID:1356885

Abstract

Plasmid pGE203 contains the Rhizobium leguminosarum biovar phaseoli glnT locus. Glutamine synthetase III (GSIII) was purified from a glutamine auxotrophic strain of Klebsiella pneumoniae carrying this plasmid. Sequencing of a 2.4-kb fragment containing the glnT locus reveals an open reading frame of 435 amino acids (aa), whose first eight aa are identical to those determined from pure GSIII by direct aa sequencing, thus confirming that glnT indeed codes for GSIII activity. The comparison of the GSIII aa sequence with the reported sequence of GSs from other organisms shows a significant degree of homology. Since the three-dimensional structure of GS from Salmonella typhimurium is known, a three-dimensional model of GSIII was built by homology.

摘要

质粒pGE203含有菜豆根瘤菌生物变种phaseoli的glnT基因座。谷氨酰胺合成酶III（GSIII）是从携带该质粒的肺炎克雷伯菌谷氨酰胺营养缺陷型菌株中纯化得到的。对包含glnT基因座的2.4 kb片段进行测序，发现一个由435个氨基酸（aa）组成的开放阅读框，其前八个氨基酸与通过直接氨基酸测序从纯GSIII中确定的氨基酸相同，从而证实glnT确实编码GSIII活性。将GSIII氨基酸序列与其他生物体中报道的谷氨酰胺合成酶（GS）序列进行比较，发现有显著程度的同源性。由于鼠伤寒沙门氏菌GS的三维结构已知，因此通过同源性构建了GSIII的三维模型。