4JPR

Structure of the ASLV fusion subunit core

4JPR の概要

• エントリーDOI: 10.2210/pdb4jpr/pdb
• 関連するPDBエントリー: 4JF3 4JGS
• 分子名称: ASLV fusion TM, CHLORIDE ION (3 entities in total)
• 機能のキーワード: alpha-helix six-helix bundle, membrane fusion, viral protein
• 由来する生物種: Rous sarcoma virus (strain Schmidt-Ruppin A) (ASLV)
• 細胞内の位置: Transmembrane protein: Virion membrane; Single-pass type I membrane protein (By similarity). Surface protein: Virion membrane; Peripheral membrane protein: P03397
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 10746.43

構造登録者

Aydin, H.,Smrke, B.M.,Lee, J.E. (登録日: 2013-03-19, 公開日: 2013-10-02, 最終更新日: 2024-11-06)

主引用文献

Aydin, H.,Smrke, B.M.,Lee, J.E.
Structural characterization of a fusion glycoprotein from a retrovirus that undergoes a hybrid 2-step entry mechanism.
Faseb J., 27:5059-5071, 2013

PubMed Abstract: Entry of enveloped viruses into host cells is mediated by their surface envelope glycoproteins (Env). On the surface of the virus, Env is in a metastable, prefusion state, primed to catalyze the fusion of the viral and host membranes. An external trigger is needed to promote the drastic conformational changes necessary for the fusion subunit to fold into the low-energy, 6-helix bundle. These triggers typically facilitate pH-independent entry at the plasma membrane or pH-dependent entry in a low-pH endosomal compartment. The α-retrovirus avian sarcoma leukosis virus (ASLV) has a rare, 2-step entry mechanism with both pH-dependent and pH-independent features. Here, we present the 2.0-Å-resolution crystal structure of the ASLV transmembrane (TM) fusion protein. Our structural and biophysical studies indicated that unlike other pH-dependent or pH-independent viral TMs, the ASLV fusion subunit is stable irrespective of pH. Two histidine residues (His490 and His492) in the chain reversal region confer stability at low pH. A structural comparison of class I viral fusion proteins suggests that the presence of a positive charge, either a histidine or arginine amino acid, stabilizes a helical dipole moment and is a signature of fusion proteins active at low pH. The structure now reveals key residues and features that explain its 2-step mechanism, and we discuss the implications of the ASLV TM structure in the context of general mechanisms required for membrane fusion.

PubMed: 24036886
DOI: 10.1096/fj.13-232371

実験手法

X-RAY DIFFRACTION (2.001 Å)