9YF8

N4 Full Virion Portal

これはPDB形式変換不可エントリーです。

9YF8 の概要

• エントリーDOI: 10.2210/pdb9yf8/pdb
• EMDBエントリー: 72880
• 分子名称: Probable portal protein (1 entity in total)
• 機能のキーワード: dodecamer, bacteriophage portal, viral protein
• 由来する生物種: Escherichia phage N4
• タンパク質・核酸の鎖数: 12
• 化学式量合計: 1027710.28

構造登録者

Bellis, N.F.,Cingolani, G. (登録日: 2025-09-25, 公開日: 2025-12-24)

主引用文献

Bellis, N.F.,Lokareddy, R.K.,Pavlenok, M.,Horton, S.L.C.,Kizziah, J.L.,Forti, F.,Schneider, D.A.,Niederweis, M.,Briani, F.,Cingolani, G.
Structure of the giant RNA polymerase ejected from coliphage N4.
Res Sq, 2025

PubMed Abstract: are widespread prokaryotic viruses that encapsidate a giant (~3,500-residue) virion-associated RNA polymerase (vRNAP). During infection, vRNAP is expelled into Gram-negative bacteria, along with two additional ejection proteins, to assemble a transient DNA-ejectosome that becomes transcriptionally active, initiating viral replication. Here, we present an integrative structural analysis of the coliphage N4 vRNAP (gp50). We find that this 383 kDa enzyme is a multi-domain, single-chain RNA polymerase, structurally distinct from both compact single-chain RNAPs and large multi-subunit holoenzymes. vRNAP is composed of loosely connected domains and exhibits an intramolecular mode of allosteric regulation through its C-terminal domain. Comparative analysis of intact and genome-released virions identified gp51, which forms an outer-membrane complex, and gp52, which assembles a periplasmic tunnel. These proteins generate heterogeneous pores that facilitate the release of vRNAP. We further uncover a signaling hub in the phage tail, composed of the receptor-binding protein, tail tube, and tail plug, that detects receptor engagement and orchestrates the release of ejection proteins. We propose that the beads-on-a-string architecture of vRNAP enables the translocation of megadalton-scale protein complexes through the ~35 Å channel formed by the tail and ejection proteins. These findings establish N4 as a distinctive model for protein translocation through biological channels.

PubMed: 41282253
DOI: 10.21203/rs.3.rs-7746245/v1

実験手法

ELECTRON MICROSCOPY (2.9 Å)