5AKA

EM structure of ribosome-SRP-FtsY complex in closed state

5AKA の概要

• エントリーDOI: 10.2210/pdb5aka/pdb
• EMDBエントリー: 2917
• 分子名称: 50S RIBOSOMAL PROTEIN L32, 23S ribosomal RNA, 50S RIBOSOMAL PROTEIN L2, ... (36 entities in total)
• 機能のキーワード: protein targeting, signal recognition particle, signal sequence, ribosome
• 由来する生物種: ESCHERICHIA COLI K-12; 詳細
• 細胞内の位置: Cytoplasm: P0AGD7
• タンパク質・核酸の鎖数: 34
• 化学式量合計: 1394621.72

構造登録者

von Loeffelholz, O.,Jiang, Q.,Ariosa, A.,Karuppasamy, M.,Huard, K.,Berger, I.,Shan, S.,Schaffitzel, C. (登録日: 2015-03-03, 公開日: 2015-03-25, 最終更新日: 2024-05-08)

主引用文献

von Loeffelholz, O.,Jiang, Q.,Ariosa, A.,Karuppasamy, M.,Huard, K.,Berger, I.,Shan, S.,Schaffitzel, C.
Ribosome-Srp-Ftsy Cotranslational Targeting Complex in the Closed State.
Proc.Natl.Acad.Sci.USA, 112:3943-3948, 2015

PubMed Abstract: The signal recognition particle (SRP)-dependent pathway is essential for correct targeting of proteins to the membrane and subsequent insertion in the membrane or secretion. In Escherichia coli, the SRP and its receptor FtsY bind to ribosome-nascent chain complexes with signal sequences and undergo a series of distinct conformational changes, which ensures accurate timing and fidelity of protein targeting. Initial recruitment of the SRP receptor FtsY to the SRP-RNC complex results in GTP-independent binding of the SRP-FtsY GTPases at the SRP RNA tetraloop. In the presence of GTP, a closed state is adopted by the SRP-FtsY complex. The cryo-EM structure of the closed state reveals an ordered SRP RNA and SRP M domain with a signal sequence-bound. Van der Waals interactions between the finger loop and ribosomal protein L24 lead to a constricted signal sequence-binding pocket possibly preventing premature release of the signal sequence. Conserved M-domain residues contact ribosomal RNA helices 24 and 59. The SRP-FtsY GTPases are detached from the RNA tetraloop and flexible, thus liberating the ribosomal exit site for binding of the translocation machinery.

PubMed: 25775537
DOI: 10.1073/PNAS.1424453112

実験手法

ELECTRON MICROSCOPY (5.7 Å)