2IPC

Crystal structure of the translocation ATPase SecA from Thermus thermophilus reveals a parallel, head-to-head dimer

2IPC の概要

• エントリーDOI: 10.2210/pdb2ipc/pdb
• 分子名称: Preprotein translocase SecA subunit (2 entities in total)
• 機能のキーワード: nucleotide binding fold, atpase, parallel dimer, structural genomics, riken structural genomics/proteomics initiative, rsgi, transport protein
• 由来する生物種: Thermus thermophilus
• 細胞内の位置: Cell inner membrane; Peripheral membrane protein; Cytoplasmic side (By similarity): Q5SIW3
• タンパク質・核酸の鎖数: 4
• 化学式量合計: 456528.88

構造登録者

Vassylyev, D.G.,Mori, H.,Vassylyeva, M.N.,Tsukazaki, T.,Kimura, Y.,Tahirov, T.H.,Ito, K.,RIKEN Structural Genomics/Proteomics Initiative (RSGI) (登録日: 2006-10-12, 公開日: 2006-11-28, 最終更新日: 2024-02-21)

主引用文献

Vassylyev, D.G.,Mori, H.,Vassylyeva, M.N.,Tsukazaki, T.,Kimura, Y.,Tahirov, T.H.,Ito, K.
Crystal Structure of the Translocation ATPase SecA from Thermus thermophilus Reveals a Parallel, Head-to-Head Dimer.
J.Mol.Biol., 364:248-258, 2006

PubMed Abstract: The mechanism of pre-protein export through the bacterial cytoplasmic membrane, in which the SecA ATPase plays a crucial role as an "energy supplier", is poorly understood. In particular, biochemical and structural studies provide contradictory data as to the oligomeric state of SecA when it is integrated into the active trans-membrane translocase. Here, we report the 2.8 A resolution crystal structure of the Thermus thermophilus SecA protein (TtSecA). Whereas the structure of the TtSecA monomer closely resembles that from other bacteria, the oligomeric state of TtSecA is strikingly distinct. In contrast to the antiparallel (head-to-tail) dimerization reported previously for the other bacterial systems, TtSecA forms parallel (head-to-head) dimers that are reminiscent of open scissors. The dimer interface is abundant in bulky Arg and Lys side-chains from both subunits, which stack on one another to form an unusual "basic zipper" that is highly conserved, as revealed by homology modeling and sequence analysis. The basic zipper is sealed on both ends by two pairs of the salt bridges formed between the basic side-chains from the zipper and two invariant acidic residues. The organization of the dimers, in which the two pre-protein binding domains are located proximal to each other at the tip of the "scissors", might allow a concerted mode of substrate recognition while the opening/closing of the scissors might facilitate translocation.

PubMed: 17059823
DOI: 10.1016/j.jmb.2006.09.061

実験手法

X-RAY DIFFRACTION (2.8 Å)