yigP——大肠杆菌生长所必需的基因

yigP——An Essential Gene for Escherichia coli Growth

yigP基因在大肠杆菌基因组上位于辅酶Q生物合成相关基因ubiE和ubiB之间,3者构成一个操纵子。利用温敏质粒pMAK705系统敲除大肠杆菌基因组上的yigP基因后,发现二次重组子内的温敏质粒无法通过高温培养丢失,即染色体上的yigP基因被敲除后,必须依靠质粒上完整的yigP基因才能存活;通过功能回补yigP基因的表达质粒pLac-yigP后,温敏质粒可以丢失;而将yigP基因分段获得的亚克隆回补yigP基因缺陷株,发现其下游367 bp的yigP-P4P2片段足以回补染色体上yigP基因的功能缺陷,从而表明yigP是大肠杆菌生长所必需的基因,且最小功能片段等于甚至小于367 bp。

The yigP gene is located between ubiE and ubiB gene which concerned CoQ biosynthesis process of Escherichia coli.These three genes are transcribed as an operon.After inactivation of the gene yigP located at chromosome by the system of temperature-sensitive plasmid pMAK705,we found that the temperature-sensitive-plasmid in sub-recombinant couldn＇t be lost at high temperature cultivation.In other words,knockout yigP of chromosome could cause Escherichia coli（E.coli） inviability only when it had complete yigP in plasmid.Through anaplerotic experiment we found that both pLac-yigP and the DNA fragment yigP-P4P2 could transform into the yigP gene deficiency variant strain.It showed that gene yigP is essential for the growth of E.coil,and the functional region of yigP gene could shrink to yigP-P4P2 domain of 367 bp.