伤寒沙门氏菌新型外膜蛋白编码基因ompS1的分离与鉴定

Isolation and characterization of ompS1, a novel Salmonella typhi outer membrane protein-encoding gene.

作者信息

Fernández-Mora M, Oropeza R, Puente J L, Calva E

机构信息

Departamento de Microbiología Molecular, Universidad Nacional Autónoma de México, Cuernavaca, Morelos.

出版信息

Gene. 1995 May 26;158(1):67-72. doi: 10.1016/0378-1119(95)00171-2.

DOI:10.1016/0378-1119(95)00171-2

PMID:7789812

Abstract

We have isolated a novel outer membrane protein (OMP)-encoding gene from Salmonella typhi (St), termed ompS1, using the ompF gene of Escherichia coli (Ec) as a heterologous probe. The structural ompS1 gene codes for an OmpS1 polypeptide that consists of 373 amino acids (aa) in the mature product, with a putative 21-aa leader sequence, containing highly conserved aa residues that have been implicated in pore formation. Mature OmpS1 (41 kDa) is larger than the OmpC, OmpF and PhoE St and Ec porins. In contrast to the major porins, it is undetectable in Coomassie-stained OMP preparations; although, when ompS1 was cloned into a high-copy-number plasmid under the control of the inducible tac promoter, it was detectable along with major OMPs. The 5' regulatory region of ompS1 has five putative binding sites for OmpR, a positive transcriptional regulator. The ompS1 gene shows restriction-fragment length polymorphism (RFLP) among Salmonellae.

摘要

我们以大肠杆菌（Ec）的ompF基因作为异源探针，从伤寒沙门氏菌（St）中分离出一个新的编码外膜蛋白（OMP）的基因，命名为ompS1。ompS1结构基因编码一种OmpS1多肽，其成熟产物由373个氨基酸（aa）组成，带有一个推定的21个氨基酸的前导序列，含有与孔形成有关的高度保守的氨基酸残基。成熟的OmpS1（41 kDa）比OmpC、OmpF和PhoE St及Ec孔蛋白更大。与主要孔蛋白不同，在考马斯亮蓝染色的OMP制剂中检测不到它；然而，当ompS1在可诱导的tac启动子控制下克隆到高拷贝数质粒中时，它与主要OMP一起可被检测到。ompS1的5'调控区有五个推定的OmpR结合位点，OmpR是一种正转录调节因子。ompS1基因在沙门氏菌中表现出限制性片段长度多态性（RFLP）。