Overhoff B, Klein M, Spies M, Freudl R
Institut für Biotechnologie 1, Forschungszentrum Jülich, Federal Republic of Germany.
Mol Gen Genet. 1991 Sep;228(3):417-23. doi: 10.1007/BF00260635.
A DNA fragment that codes for the 364 amino-terminal amino acid residues of a putative Bacillus subtilis SecA homologue has been cloned using the Escherichia coli secA gene as a probe. The deduced amino acid sequence showed 58% identity to the amino-terminus of the E. coli SecA protein. A DNA fragment which codes for 275 amino-terminal amino acid residues of the B. subtilis SecA homologue was expressed in E. coli and the corresponding gene product was shown to be recognized by anti-E. coli SecA antibodies. This polypeptide, although only about 30% the size of the E. coli SecA protein, also restored growth of E. coli MM52 (secAts) at the non-permissive temperature and the translocation defect of proOmpA in this mutant was relieved to a substantial extent.
利用大肠杆菌secA基因作为探针，克隆了一段编码推测的枯草芽孢杆菌SecA同源物364个氨基末端氨基酸残基的DNA片段。推导的氨基酸序列与大肠杆菌SecA蛋白的氨基末端显示出58%的同一性。一段编码枯草芽孢杆菌SecA同源物275个氨基末端氨基酸残基的DNA片段在大肠杆菌中表达，并且相应的基因产物被抗大肠杆菌SecA抗体识别。这种多肽虽然大小仅约为大肠杆菌SecA蛋白的30%，但也恢复了大肠杆菌MM52（secAts）在非允许温度下的生长，并且该突变体中proOmpA的转运缺陷在很大程度上得到了缓解。
