Felmlee T, Welch R A
Department of Medical Microbiology, University of Wisconsin Medical School, Madison 53706.
Proc Natl Acad Sci U S A. 1988 Jul;85(14):5269-73. doi: 10.1073/pnas.85.14.5269.
The primary structure of the Escherichia coli hemolysin polypeptide (HlyA) is used to predict intramolecular structures involved in the secretion and cytolytic activity of the molecule. The C-terminal region of HlyA contains a repeated, 8-amino acid chain represented by the consensus sequence Leu-Xaa-Gly-Gly-Xaa-Gly-Asn-Asp. Three in vitro derived mutations of hlyA are described that encode molecules missing various portions of the C-terminal region, including the repeat region. The wild-type and mutated HlyA molecules were analyzed for the ability to be secreted and to lyse erythrocytes. Hemolytic activity absolutely requires the presence of the repeats. The ability of the mutated HlyA molecules to initiate membrane translocation and be secreted required the presence of the C terminus and, to a degree, the repeated amino acid octets.
大肠杆菌溶血素多肽（HlyA）的一级结构用于预测参与该分子分泌和细胞溶解活性的分子内结构。HlyA的C末端区域包含一个重复的8氨基酸链，其共有序列为Leu-Xaa-Gly-Gly-Xaa-Gly-Asn-Asp。描述了hlyA的三个体外衍生突变，它们编码缺失C末端区域不同部分（包括重复区域）的分子。分析了野生型和突变型HlyA分子的分泌能力和裂解红细胞的能力。溶血活性绝对需要重复序列的存在。突变型HlyA分子启动膜转运和分泌的能力需要C末端的存在，并且在一定程度上需要重复的八联体氨基酸。
