GENETIC-EVIDENCE FOR SUBSTRATE AND PERIPLASMIC-BINDING-PROTEIN RECOGNITION BY THE MALF AND MALG PROTEINS, CYTOPLASMIC MEMBRANE-COMPONENTS OF THE ESCHERICHIA-COLI MALTOSE TRANSPORT-SYSTEM
GENETIC-EVIDENCE FOR SUBSTRATE AND PERIPLASMIC-BINDING-PROTEIN RECOGNITION BY THE MALF AND MALG PROTEINS, CYTOPLASMIC MEMBRANE-COMPONENTS OF THE ESCHERICHIA-COLI MALTOSE TRANSPORT-SYSTEM
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DOI：
10.1128/jb.163.2.654-660.1985
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发表时间：
1985-01-01
影响因子：
3.2
通讯作者：
SHUMAN, HA
中科院分区：
文献类型：
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作者：
TREPTOW, NA;SHUMAN, HA
大肠杆菌的突变体不再需要在麦芽糖上生长麦芽糖结合蛋白（MBP），因为分离了C和能量的唯一来源。这些突变体被选为菌株的MAL+恢复物，该菌株携带MBP结构基因的缺失，男性。在这些突变体的1类中，麦芽糖通过麦芽糖系统的其余成分独立于MBP运输到细胞中。这些菌株中的突变映射在MALF或MALG中。这些基因为麦芽糖传输系统的2个细胞质膜成分编码。在某些突变体中，MBP实际上抑制了麦芽糖的运输。这些突变体仍然以立体特定的方式积极运输麦芽糖。这些结果表明，MALF和MALG突变导致底物识别位点暴露，这通常仅适用于与MBP结合的底物。
Mutants of E. coli in which the maltose-binding protein (MBP) is no longer required for growth on maltose as the sole source of C and energy were isolated. These mutants were selected as Mal+ revertants of a strain which carries a deletion of the MBP structural gene, malE. In 1 class of these mutants, maltose is transported into the cell independently of MBP by the remaining components of the maltose system. The mutations in these strains map in either malF or malG. These genes code for 2 of the cytoplasmic membrane components of the maltose transport system. In some of the mutants, MBP actually inhibits maltose transport. These mutants still transport maltose actively and in a stereospecific manner. These results suggest that the malF and malG mutations result in exposure of a substrate recognition site that is usually available only to substrates bound to MBP.