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-Structure paper
タイトル | Structural basis for DNA recognition by a viral genome-packaging machine. |
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ジャーナル・号・ページ | Proc Natl Acad Sci U S A, Vol. 121, Issue 33, Page e2406138121, Year 2024 |
掲載日 | 2024年8月13日 |
著者 | Maria Chechik / Sandra J Greive / Alfred A Antson / Huw T Jenkins / |
PubMed 要旨 | 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 ...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. |
リンク | Proc Natl Acad Sci U S A / PubMed:39116131 / PubMed Central |
手法 | EM (単粒子) |
解像度 | 2.92 - 3.0 Å |
構造データ | EMDB-17794: HK97 small terminase in complex with DNA after focused classification EMDB-17818: Complex of HK97 small terminase with DNA |
由来 |
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キーワード | DNA BINDING PROTEIN / small terminase / HK97 / bacteriophage / complex with DNA |