1M74

Crystal structure of Mg-ADP-bound SecA from Bacillus subtilis

1M74 の概要

• エントリーDOI: 10.2210/pdb1m74/pdb
• 関連するPDBエントリー: 1M6N
• 分子名称: Preprotein translocase secA, MAGNESIUM ION, SULFATE ION, ... (5 entities in total)
• 機能のキーワード: protein translocation; atpase; transmembrane transport; helicase family structure; mechanochemisty, protein transport
• 由来する生物種: Bacillus subtilis
• 細胞内の位置: Cell membrane; Peripheral membrane protein; Cytoplasmic side (By similarity): P28366
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 92325.58

構造登録者

Hunt, J.F.,Weinkauf, S.,Henry, L.,Fak, J.J.,McNicholas, P.,Oliver, D.B.,Deisenhofer, J. (登録日: 2002-07-16, 公開日: 2002-09-20, 最終更新日: 2024-02-14)

主引用文献

Hunt, J.F.,Weinkauf, S.,Henry, L.,Fak, J.J.,McNicholas, P.,Oliver, D.B.,Deisenhofer, J.
Nucleotide Control of Interdomain Interactions in the Conformational Reaction Cycle of SecA
Science, 297:2018-2026, 2002

PubMed Abstract: The SecA adenosine triphosphatase (ATPase) mediates extrusion of the amino termini of secreted proteins from the eubacterial cytosol based on cycles of reversible binding to the SecYEG translocon. We have determined the crystal structure of SecA with and without magnesium-adenosine diphosphate bound to the high-affinity ATPase site at 3.0 and 2.7 angstrom resolution, respectively. Candidate sites for preprotein binding are located on a surface containing the SecA epitopes exposed to the periplasm upon binding to SecYEG and are thus positioned to deliver preprotein to SecYEG. Comparisons with structurally related ATPases, including superfamily I and II ATP-dependent helicases, suggest that the interaction geometry of the tandem motor domains in SecA is modulated by nucleotide binding, which is shown by fluorescence anisotropy experiments to reverse an endothermic domain-dissociation reaction hypothesized to gate binding to SecYEG.

PubMed: 12242434
DOI: 10.1126/science.1074424

実験手法

X-RAY DIFFRACTION (3 Å)