Benson S A, Decloux A
J Bacteriol. 1985 Jan;161(1):361-7. doi: 10.1128/jb.161.1.361-367.1985.
Escherichia coli normally requires the lamB gene for the uptake of maltodextrins. We have identified and characterized three independent mutations that allow E. coli to grow on maltodextrin in the absence of a functional lamB gene by allowing maltodextrins with a molecular weight greater than 1,000 to cross the outer membrane barrier. Two of the mutations map to the structural gene for the outer membrane porin OmpF, and the remaining mutation maps to the structural gene for the second major outer membrane porin, OmpC. These mutations increase the permeability of the outer membrane to small hydrophilic substances, antibiotics, and detergents. These mutations alter the electrophoretic mobility of the respective porin proteins.
大肠杆菌通常需要lamB基因来摄取麦芽糊精。我们已经鉴定并表征了三个独立的突变，这些突变通过允许分子量大于1000的麦芽糊精穿过外膜屏障，使大肠杆菌在没有功能性lamB基因的情况下能够在麦芽糊精上生长。其中两个突变定位于外膜孔蛋白OmpF的结构基因，其余突变定位于第二个主要外膜孔蛋白OmpC的结构基因。这些突变增加了外膜对小的亲水性物质、抗生素和去污剂的通透性。这些突变改变了各自孔蛋白的电泳迁移率。
