Distinct quaternary structures of the AAA plus Lon protease control substrate degradation

被引：56

作者：

Vieux, Ellen F. ^{[1
]}

Wohlever, Matthew L. ^{[1
]}

Chen, James Z. ^{[1
]}

Sauer, Robert T. ^{[1
]}

Baker, Tania A. ^{[1
,2
]}

机构：

[1] MIT, Dept Biol, Cambridge, MA 02139 USA

[2] MIT, Howard Hughes Med Inst, Cambridge, MA 02139 USA

来源：

PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA | 2013年 / 110卷 / 22期

基金：

美国国家卫生研究院; 美国国家科学基金会;

关键词：

ATP-dependent protease; EM structure; IbpB; substrate gating; regulated proteolysis; IN-VITRO DEGRADATION; HEAT-SHOCK PROTEINS; ESCHERICHIA-COLI; ION-GENE; MITOCHONDRIAL LON; AMINO-ACID; PROTEOLYSIS; SEQUENCE; IBPB; SULA;

D O I：

10.1073/pnas.1307066110

中图分类号：

O [数理科学和化学]; P [天文学、地球科学]; Q [生物科学]; N [自然科学总论];

学科分类号：

070301 [无机化学]; 070403 [天体物理学]; 070507 [自然资源与国土空间规划学]; 090105 [作物生产系统与生态工程];

摘要：

Lon is an ATPase associated with cellular activities (AAA+) protease that controls cell division in response to stress and also degrades misfolded and damaged proteins. Subunits of Lon are known to assemble into ring-shaped homohexamers that enclose an internal degradation chamber. Here, we demonstrate that hexamers of Escherichia coli Lon also interact to form a dodecamer at physiological protein concentrations. Electron microscopy of this dodecamer reveals a prolate structure with the protease chambers at the distal ends and a matrix of N domains forming an equatorial hexamer-hexamer interface, with portals of similar to 45 angstrom providing access to the enzyme lumen. Compared with hexamers, Lon dodecamers are much less active in degrading large substrates but equally active in degrading small substrates. Our results support a unique gating mechanism that allows the repertoire of Lon substrates to be tuned by its assembly state.

引用

页码：E2002 / E2008

页数：7

共 51 条

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