Suh Y, Benedik M J
Department of Biochemical and Biophysical Sciences, University of Houston, Texas 77204-5934.
J Bacteriol. 1992 Apr;174(7):2361-6. doi: 10.1128/jb.174.7.2361-2366.1992.
Serratia marcescens produces an abundant extracellular metalloprotease. The gene for this protease had previously been cloned and expressed in Escherichia coli, in which no functional protease could be found. However, the protease gene carries the LXGGXGND repeat motif found in alpha-hemolysin and other proteins secreted by homologous systems. Using a dual-plasmid complementation system, we show that the alpha-hemolysin hlyB and hlyD transport determinants are sufficient to allow secretion and activation of a functional metalloprotease species from E. coli, as are the comparable protease secretion functions of Erwinia chrysanthemi. However, strains expressing protease with the hlyBD transport system are unstable and rapidly lose the ability to produce functional protease.
粘质沙雷氏菌产生大量细胞外金属蛋白酶。该蛋白酶的基因先前已被克隆并在大肠杆菌中表达，但在大肠杆菌中未发现有功能的蛋白酶。然而，该蛋白酶基因携带在α-溶血素和同源系统分泌的其他蛋白质中发现的LXGGXGND重复基序。使用双质粒互补系统，我们表明α-溶血素hlyB和hlyD转运决定簇足以使功能性金属蛋白酶从大肠杆菌中分泌和激活，菊欧文氏菌的类似蛋白酶分泌功能也足以做到这一点。然而，用hlyBD转运系统表达蛋白酶的菌株不稳定，会迅速失去产生功能性蛋白酶的能力。
