negative regulation of establishment of competence for transformation / negative regulation of sporulation resulting in formation of a cellular spore / establishment of competence for transformation / sporulation resulting in formation of a cellular spore / protein folding chaperone / protein-macromolecule adaptor activity / ATP hydrolysis activity / ATP binding 類似検索 - 分子機能
MecA, C-terminal domain superfamily / Negative regulator of genetic competence, MecA / Negative regulator of genetic competence (MecA) / UVR domain / UVR domain profile. / ClpA/B, conserved site 2 / Chaperonins clpA/B signature 2. / ClpA/B, conserved site 1 / Chaperonins clpA/B signature 1. / ClpA/ClpB, AAA lid domain ...MecA, C-terminal domain superfamily / Negative regulator of genetic competence, MecA / Negative regulator of genetic competence (MecA) / UVR domain / UVR domain profile. / ClpA/B, conserved site 2 / Chaperonins clpA/B signature 2. / ClpA/B, conserved site 1 / Chaperonins clpA/B signature 1. / ClpA/ClpB, AAA lid domain / AAA lid domain / : / Clp repeat (R) N-terminal domain / Clp repeat (R) domain profile. / Clp, repeat (R) domain / Clp, N-terminal domain superfamily / ClpA/B family / Clp ATPase, C-terminal / C-terminal, D2-small domain, of ClpB protein / C-terminal, D2-small domain, of ClpB protein / AAA domain (Cdc48 subfamily) / ATPase family associated with various cellular activities (AAA) / ATPase, AAA-type, core / ATPases associated with a variety of cellular activities / AAA+ ATPase domain / P-loop containing nucleoside triphosphate hydrolase 類似検索 - ドメイン・相同性
Negative regulator of genetic competence ClpC/MecB / Adapter protein MecA 1 類似検索 - 構成要素
ジャーナル: J Biol Chem / 年: 2013 タイトル: Structural dynamics of the MecA-ClpC complex: a type II AAA+ protein unfolding machine. 著者: Jing Liu / Ziqing Mei / Ningning Li / Yutao Qi / Yanji Xu / Yigong Shi / Feng Wang / Jianlin Lei / Ning Gao / 要旨: 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 ...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.
電子線照射量: 20 e/Å2 / フィルム・検出器のモデル: FEI EAGLE (4k x 4k)
放射波長
相対比: 1
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解析
EMソフトウェア
ID
名称
カテゴリ
1
MDFF
モデルフィッティング
2
SPIDER
3次元再構成
CTF補正
詳細: each defocus group on 3D level
対称性
点対称性: C1 (非対称)
3次元再構成
手法: Reference Projections / 解像度: 9 Å / 解像度の算出法: FSC 0.5 CUT-OFF / 粒子像の数: 45514 / 詳細: Single particle--Applied symmetry: C6 / 対称性のタイプ: POINT
原子モデル構築
プロトコル: FLEXIBLE FIT / 空間: REAL / Target criteria: Cross-correlation 詳細: REFINEMENT PROTOCOL--flexible DETAILS--Protocol- Initial local fitting was done using Chimera and then MDFF was used for flexible fitting. ref- Trabuco, L.G., Villa, E., Mitra, K., Frank, J. ...詳細: REFINEMENT PROTOCOL--flexible DETAILS--Protocol- Initial local fitting was done using Chimera and then MDFF was used for flexible fitting. ref- Trabuco, L.G., Villa, E., Mitra, K., Frank, J. and Schulten, K. (2008) Flexible fitting of atomic structures into electron microscopy maps using molecular dynamics.