Collier D N
Central Research and Development Division, E. I. DuPont de Nemours & Co., Wilmington, Delaware 19880-0328.
J Bacteriol. 1994 Aug;176(16):4937-40. doi: 10.1128/jb.176.16.4937-4940.1994.
Less than 20% of the Escherichia coli maltose-binding protein (MBP) synthesized in Bacillus subtilis is exported. However, a portion of the secreted MBP was processed cotranslationally. Coexpression of SecB, a secretion-related chaperone of E. coli, stimulated posttranslational export of MBP in B. subtilis but inhibited its cotranslational processing. Export of a SecB-independent MBP-ribose-binding protein hybrid precursor was not enhanced by SecB. A slowly folding MBP derivative (MBP-Y283D) was more efficiently secreted than wild-type MBP, suggesting that the antifolding activity of SecB promotes posttranslational secretion of MBP in B. subtilis.
在枯草芽孢杆菌中合成的大肠杆菌麦芽糖结合蛋白(MBP)只有不到20%被分泌。然而,一部分分泌的MBP是共翻译加工的。大肠杆菌分泌相关伴侣蛋白SecB的共表达刺激了枯草芽孢杆菌中MBP的翻译后分泌,但抑制了其共翻译加工。SecB对不依赖SecB的MBP-核糖结合蛋白杂交前体的分泌没有增强作用。一种折叠缓慢的MBP衍生物(MBP-Y283D)比野生型MBP分泌效率更高,这表明SecB的抗折叠活性促进了枯草芽孢杆菌中MBP的翻译后分泌。