期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：1974
卷号：71
期号：10
页码：4178-4182
DOI：10.1073/pnas.71.10.4178
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：The three dimensional structure of the lysozyme from bacteriophage T4 has been determined from a 2.5 A resolution electron density map. About 60% of the molecule is in a helical conformation and there is one region consisting of antiparallel {beta}-structure. The polypeptide backbone folds into two distinct lobes linked in part by a long helix. In the region between the two lobes, there is a cleft which deepens into a hole or cavity, about 6-8 A in diameter, extending from one side of the molecule to the other. This opening is closed off by side chains which extend to within 3-5 A of each other. A number of mutant lysozymes in which residues in the vicinity of the opening are modified have markedly reduced catalytic activity, suggesting that this region of the molecule may be catalytically important. The three dimensional structure of T4 phage lysozyme is quite different from that of hen egg-white lysozyme although it is not clear at this time whether or not the mechanisms of catalysis of the respective enzymes are related.
