文章基本信息

标题：The catalytic sites of 20S proteasomes and their role in subunit maturation: A mutational and crystallographic study
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作者：Michael Groll ; Wolfgang Heinemeyer ; Sibylle Jäger 等
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：1999
卷号：96
期号：20
页码：10976-10983
DOI：10.1073/pnas.96.20.10976
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：We present a biochemical and crystallographic characterization of active site mutants of the yeast 20S proteasome with the aim to characterize substrate cleavage specificity, subunit intermediate processing, and maturation. {beta}1(Pre3), {beta}2(Pup1), and {beta}5(Pre2) are responsible for the postacidic, tryptic, and chymotryptic activity, respectively. The maturation of active subunits is independent of the presence of other active subunits and occurs by intrasubunit autolysis. The propeptides of {beta}6(Pre7) and {beta}7(Pre4) are intermediately processed to their final forms by {beta}2(Pup1) in the wild-type enzyme and by {beta}5(Pre2) and {beta}1(Pre3) in the {beta}2(Pup1) inactive mutants. A role of the propeptide of {beta}1(Pre3) is to prevent acetylation and thereby inactivation. A gallery of proteasome mutants that contain active site residues in the context of the inactive subunits {beta}3(Pup3), {beta}6(Pre7), and {beta}7(Pre4) show that the presence of Gly-1, Thr1, Asp17, Lys33, Ser129, Asp166, and Ser169 is not sufficient to generate activity.