3J3S
Structural dynamics of the MecA-ClpC complex revealed by cryo-EM
3J3S の概要
| エントリーDOI | 10.2210/pdb3j3s/pdb |
| 関連するPDBエントリー | 3J3R 3J3T 3J3U |
| EMDBエントリー | 5608 |
| 分子名称 | Adapter protein MecA 1, Negative regulator of genetic competence ClpC/MecB (2 entities in total) |
| 機能のキーワード | clpc, meca, aaa+ atpase, protein unfolding, chaperone |
| 由来する生物種 | Bacillus subtilis 詳細 |
| タンパク質・核酸の鎖数 | 12 |
| 化学式量合計 | 695911.78 |
| 構造登録者 | |
| 主引用文献 | Liu, J.,Mei, Z.,Li, N.,Qi, Y.,Xu, Y.,Shi, Y.,Wang, F.,Lei, J.,Gao, N. Structural dynamics of the MecA-ClpC complex: a type II AAA+ protein unfolding machine. J.Biol.Chem., 288:17597-17608, 2013 Cited by PubMed Abstract: The MecA-ClpC complex is a bacterial type II AAA(+) molecular machine responsible for regulated unfolding of substrates, such as transcription factors ComK and ComS, and targeting them to ClpP for degradation. The six subunits of the MecA-ClpC complex form a closed barrel-like structure, featured with three stacked rings and a hollow passage, where substrates are threaded and translocated through successive pores. Although the general concepts of how polypeptides are unfolded and translocated by internal pore loops of AAA(+) proteins have long been conceived, the detailed mechanistic model remains elusive. With cryoelectron microscopy, we captured four different structures of the MecA-ClpC complexes. These complexes differ in the nucleotide binding states of the two AAA(+) rings and therefore might presumably reflect distinctive, representative snapshots from a dynamic unfolding cycle of this hexameric complex. Structural analysis reveals that nucleotide binding and hydrolysis modulate the hexameric complex in a number of ways, including the opening of the N-terminal ring, the axial and radial positions of pore loops, the compactness of the C-terminal ring, as well as the relative rotation between the two nucleotide-binding domain rings. More importantly, our structural and biochemical data indicate there is an active allosteric communication between the two AAA(+) rings and suggest that concerted actions of the two AAA(+) rings are required for the efficiency of the substrate unfolding and translocation. These findings provide important mechanistic insights into the dynamic cycle of the MecA-ClpC unfoldase and especially lay a foundation toward the complete understanding of the structural dynamics of the general type II AAA(+) hexamers. PubMed: 23595989DOI: 10.1074/jbc.M113.458752 主引用文献が同じPDBエントリー |
| 実験手法 | ELECTRON MICROSCOPY (11 Å) |
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