The three-dimensional structure of Salmonella typhimurium aspartyl dipeptidase, peptidase E, was solved crystallographically and refined to 1.2-Å resolution, The structure of this 25-kDa enzyme consists of two mixed β-sheets forming a V, flanked by six α-helices. The active site contains a Ser-His-Glu catalytic triad and is the first example of a serine peptidase/protease with a glutamate in the catalytic triad. The active site Ser is located on a strand-helix motif reminiscent of that found in α/β-hydrolases, but the polypeptide fold and the organization of the catalytic triad differ from those of the known serine proteases. This enzyme is a member of a family of serine hydrolases and appears to represent a new example of convergent evolution of peptidase activity.
|頁（從 - 到）||14097-14102|
|期刊||Proceedings of the National Academy of Sciences of the United States of America|
|出版狀態||已發佈 - 12月 19 2000|
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