Singh S P, Miller S, Williams Y U, Rudd K E, Nikaido H
Biomedical Research Program, Alabama State University, Montgomery 36101, USA.
Microbiology (Reading). 1996 Nov;142 ( Pt 11):3201-10. doi: 10.1099/13500872-142-11-3201.
The OmpD porin was isolated and purified from Salmonella typhimurium strain SH 7454 (ompC::Tn10), digested with cyanogen bromide (CNBr) and the peptide fragments were separated by SDS-PAGE. N-terminal sequencing identified a total of 96 residues from four distinct peptides. The sequence showed that OmpD is homologous to NmpC (75% identity), Lc(75%) and OmpC (70%) from Escherichia coli, and OmpC (68%) from S. typhimurium. The sequence was essentially identical to the translated sequence of an nmpC-like gene of S. typhimurium, currently placed at 38.6 centisomes of the chromosome. Our results and other data suggest, however, that this gene is actually the ompD gene, which is more correctly placed in the 34 centisome region of the chromosome. The CNBr-generated peptides were also screened with 16 anti-S. typhimurium OmpD monoclonal antibodies by Western blotting. These results, in conjunction with the prediction of the OmpD folding pattern based on the known three-dimensional structure of E. coli OmpF, showed a close immunological relationship among S. typhimurium OmpD and E. coli NmpC and Lc, and a strong conservation of sequences within the transmembrane beta strands of these porins and E. coli OmpC, PhoE and OmpF, and Salmonella typhic OmpC.
从鼠伤寒沙门氏菌菌株SH 7454（ompC::Tn10）中分离并纯化出OmpD孔蛋白，用溴化氰（CNBr）进行消化，然后通过SDS-PAGE分离肽片段。N端测序从四个不同的肽段中鉴定出总共96个残基。序列显示OmpD与大肠杆菌的NmpC（75%同一性）、Lc（75%）和OmpC（70%）以及鼠伤寒沙门氏菌的OmpC（68%）同源。该序列与鼠伤寒沙门氏菌一个nmpC样基因的翻译序列基本相同，该基因目前位于染色体的38.6厘摩处。然而，我们的结果和其他数据表明，该基因实际上是ompD基因，更准确地位于染色体的34厘摩区域。还通过蛋白质印迹法用16种抗鼠伤寒沙门氏菌OmpD单克隆抗体对CNBr产生的肽段进行了筛选。这些结果，结合基于大肠杆菌OmpF已知三维结构对OmpD折叠模式的预测，表明鼠伤寒沙门氏菌OmpD与大肠杆菌NmpC和Lc之间存在密切的免疫关系，并且这些孔蛋白以及大肠杆菌OmpC、PhoE和OmpF以及鼠伤寒OmpC的跨膜β链内的序列具有高度保守性。
