Structure of a longitudinal actin dimer assembled by tandem w domains: implications for actin filament nucleation.
Structure of a longitudinal actin dimer assembled by tandem w domains: implications for actin filament nucleation.
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由串联 w 域组装的纵向肌动蛋白二聚体的结构：对肌动蛋白丝成核的影响。
DOI：
10.1016/j.jmb.2010.08.040
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发表时间：
2010
影响因子：
5.6
通讯作者：
Dominguez,Roberto
中科院分区：
文献类型：
--
作者：
Rebowski,Grzegorz;Namgoong,Suk;Boczkowska,Malgorzata;Leavis,PaulC;Navaza,Jorge;Dominguez,Roberto
Actin filament nucleators initiate polymerization in cells in a regulated manner. A common architecture among these molecules consists of tandem WASP homology 2 domains (W domains) that recruit three to four actin subunits to form a polymerization nucleus. We describe a low-resolution crystal structure of an actin dimer assembled by tandem W domains, where the first W domain is cross-linked to Cys374 of the actin subunit bound to it, whereas the last W domain is followed by the C-terminal pointed end-capping helix of thymosin β4. While the arrangement of actin subunits in the dimer resembles that of a long-pitch helix of the actin filament, important differences are observed. These differences result from steric hindrance of the W domain with intersubunit contacts in the actin filament. We also determined the structure of the first W domain of Vibrio parahaemolyticus VopL cross-linked to actin Cys374 and show it to be nearly identical with non-cross-linked W-Actin structures. This result validates the use of cross-linking as a tool for the study of actin nucleation complexes, whose natural tendency to polymerize interferes with most structural methods. Combined with a biochemical analysis of nucleation, the structures may explain why nucleators based on tandem W domains with short inter-W linkers have relatively weak activity, cannot stay bound to filaments after nucleation, and are unlikely to influence filament elongation. The findings may also explain why nucleation-promoting factors of the Arp2/3 complex, which are related to tandem-W-domain nucleators, are ejected from branch junctions after nucleation. We finally show that the simple addition of the C-terminal pointed end-capping helix of thymosin β4 to tandem W domains can change their activity from actin filament nucleation to monomer sequestration.
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影响因子：
8.8
作者：
Chapman, J D;Franko, A J;Sharplin, J
通讯作者：
Sharplin, J
溴米异硝唑：新型放射增敏剂的合成和表征。
影响因子：
3.4
作者：
J. Rasey;K. Krohn;S. Freauff
通讯作者：
S. Freauff
影响因子：
8.8
作者：
Franko, A J;Chapman, J D
通讯作者：
Chapman, J D
影响因子：
3.6
作者：
GALLO, GG;PASQUALU.CR;LANCINI, GC
通讯作者：
LANCINI, GC
米索硝唑与 EMt6 和 V79 球体的结合。
DOI：
10.1016/0360-3016(82)90724-6
发表时间：
1982
期刊：
International journal of radiation oncology, biology, physics
影响因子：
--
作者：
A. Franko;J. Chapman;Cameron J. Koch
通讯作者：
Cameron J. Koch