2FSG

Complex SecA:ATP from Escherichia coli

2FSG の概要

• エントリーDOI: 10.2210/pdb2fsg/pdb
• 関連するPDBエントリー: 1M6N 1NL3 1TF5 2FSF 2FSH 2FSI
• 分子名称: Preprotein translocase secA subunit, ADENOSINE-5'-TRIPHOSPHATE (3 entities in total)
• 機能のキーワード: atpase, dna-rna helicase, protein translocation, seca, protein transport
• 由来する生物種: Escherichia coli
• 細胞内の位置: Cell inner membrane; Peripheral membrane protein; Cytoplasmic side: P10408
• タンパク質・核酸の鎖数: 2
• 化学式量合計: 198153.96

構造登録者

Papanikolau, Y.,Petratos, K.,Economou, A. (登録日: 2006-01-23, 公開日: 2007-01-16, 最終更新日: 2024-10-23)

主引用文献

Papanikolau, Y.,Papadovasilaki, M.,Ravelli, R.B.,McCarthy, A.A.,Cusack, S.,Economou, A.,Petratos, K.
Structure of dimeric SecA, the Escherichia coli preprotein translocase motor.
J.Mol.Biol., 366:1545-1557, 2007

PubMed Abstract: SecA is the preprotein translocase ATPase subunit and a superfamily 2 (SF2) RNA helicase. Here we present the 2 A crystal structures of the Escherichia coli SecA homodimer in the apo form and in complex with ATP, ADP and adenosine 5'-[beta,gamma-imido]triphosphate (AMP-PNP). Each monomer contains the SF2 ATPase core (DEAD motor) built of two domains (nucleotide binding domain, NBD and intramolecular regulator of ATPase 2, IRA2), the preprotein binding domain (PBD), which is inserted in NBD and a carboxy-terminal domain (C-domain) linked to IRA2. The structures of the nucleotide complexes of SecA identify an interfacial nucleotide-binding cleft located between the two DEAD motor domains and residues critical for ATP catalysis. The dimer comprises two virtually identical protomers associating in an antiparallel fashion. Dimerization is mediated solely through extensive contacts of the DEAD motor domains leaving the C-domain facing outwards from the dimerization core. This dimerization mode explains the effect of functionally important mutations and is completely different from the dimerization models proposed for other SecA structures. The repercussion of these findings on translocase assembly and catalysis is discussed.

PubMed: 17229438
DOI: 10.1016/j.jmb.2006.12.049

実験手法

X-RAY DIFFRACTION (2.2 Å)