8POP

HK97 small terminase in complex with DNA

8POP の概要

• エントリーDOI: 10.2210/pdb8pop/pdb
• EMDBエントリー: 17794
• 分子名称: Terminase small subunit, DNA (31-MER) (3 entities in total)
• 機能のキーワード: small terminase, hk97, bacteriophage, complex with dna, dna binding protein
• 由来する生物種: Escherichia phage HK97; 詳細
• タンパク質・核酸の鎖数: 11
• 化学式量合計: 185536.21

構造登録者

Chechik, M.,Greive, S.J.,Antson, A.A.,Jenkins, H.T. (登録日: 2023-07-05, 公開日: 2023-08-09, 最終更新日: 2024-08-21)

主引用文献

Chechik, M.,Greive, S.J.,Antson, A.A.,Jenkins, H.T.
Structural basis for DNA recognition by a viral genome-packaging machine.
Proc.Natl.Acad.Sci.USA, 121:e2406138121-e2406138121, 2024

PubMed Abstract: DNA recognition is critical for assembly of double-stranded DNA viruses, particularly for the initiation of packaging the viral genome into the capsid. The key component that recognizes viral DNA is the small terminase protein. Despite prior studies, the molecular mechanism for DNA recognition remained elusive. Here, we address this question by identifying the minimal site in the bacteriophage HK97 genome specifically recognized by the small terminase and determining the structure of this complex by cryoEM. The circular small terminase employs an entirely unexpected mechanism in which DNA transits through the central tunnel, and sequence-specific recognition takes place as it emerges. This recognition stems from a substructure formed by the N- and C-terminal segments of two adjacent protomers which are unstructured when DNA is absent. Such interaction ensures continuous engagement of the small terminase with DNA, enabling it to slide along the DNA while simultaneously monitoring its sequence. This mechanism allows locating and instigating packaging initiation and termination precisely at the specific sequence.

PubMed: 39116131
DOI: 10.1073/pnas.2406138121

実験手法

ELECTRON MICROSCOPY (3 Å)