Bankaitis V A, Rasmussen B A, Bassford P J
Cell. 1984 May;37(1):243-52. doi: 10.1016/0092-8674(84)90320-9.
A deletion mutation, malE delta 12-18, removes seven residues from the hydrophobic core of the maltose binding protein (MBP) signal peptide and thus prevents secretion of this protein to the periplasm of E. coli. Intragenic suppressor mutations of malE delta 12-18 have been obtained, some highly efficient in their ability to restore proper MBP export. Twelve independently isolated suppressors represent six unique mutational events. Five result in alterations within the MBP signal peptide; one changes the amino acid at residue 19 of the mature MBP. Analysis of these suppressors indicates that the length of the hydrophobic core is a major determinant of signal peptide function. The experiments further suggest that the hydrophobic core region serves primarily a structural role in mediating protein secretion, and that other sequences outside of this region may be responsible for providing the initial recognition of the MBP nascent chain as a secreted protein.
一种缺失突变，即malE delta 12 - 18，从麦芽糖结合蛋白（MBP）信号肽的疏水核心中去除了七个残基，从而阻止该蛋白分泌到大肠杆菌的周质中。已获得malE delta 12 - 18的基因内抑制突变，其中一些在恢复MBP正确输出的能力方面非常高效。十二个独立分离的抑制子代表六个独特的突变事件。五个导致MBP信号肽内的改变；一个改变了成熟MBP第19位残基的氨基酸。对这些抑制子的分析表明，疏水核心的长度是信号肽功能的主要决定因素。实验进一步表明，疏水核心区域在介导蛋白质分泌中主要起结构作用，并且该区域之外的其他序列可能负责将MBP新生链初始识别为分泌蛋白。
