6Z6E

Crystal structure of the HK97 bacteriophage small terminase

Summary for 6Z6E

• Entry DOI: 10.2210/pdb6z6e/pdb
• Descriptor: Terminase small subunit, IODIDE ION (3 entities in total)
• Functional Keywords: genome packaging, bacteriophage, dna binding, viral protein
• Biological source: Enterobacteria phage HK97
• Total number of polymer chains: 3
• Total formula weight: 56241.50

Authors

Fung, H.K.H.,Chechik, M.,Baumann, C.G.,Antson, A.A. (deposition date: 2020-05-28, release date: 2021-06-09, Last modification date: 2024-06-19)

Primary citation

Fung, H.K.H.,Grimes, S.,Huet, A.,Duda, R.L.,Chechik, M.,Gault, J.,Robinson, C.V.,Hendrix, R.W.,Jardine, P.J.,Conway, J.F.,Baumann, C.G.,Antson, A.A.
Structural basis of DNA packaging by a ring-type ATPase from an archetypal viral system.
Nucleic Acids Res., 50:8719-8732, 2022

PubMed Abstract: Many essential cellular processes rely on substrate rotation or translocation by a multi-subunit, ring-type NTPase. A large number of double-stranded DNA viruses, including tailed bacteriophages and herpes viruses, use a homomeric ring ATPase to processively translocate viral genomic DNA into procapsids during assembly. Our current understanding of viral DNA packaging comes from three archetypal bacteriophage systems: cos, pac and phi29. Detailed mechanistic understanding exists for pac and phi29, but not for cos. Here, we reconstituted in vitro a cos packaging system based on bacteriophage HK97 and provided a detailed biochemical and structural description. We used a photobleaching-based, single-molecule assay to determine the stoichiometry of the DNA-translocating ATPase large terminase. Crystal structures of the large terminase and DNA-recruiting small terminase, a first for a biochemically defined cos system, reveal mechanistic similarities between cos and pac systems. At the same time, mutational and biochemical analyses indicate a new regulatory mechanism for ATPase multimerization and coordination in the HK97 system. This work therefore establishes a framework for studying the evolutionary relationships between ATP-dependent DNA translocation machineries in double-stranded DNA viruses.

PubMed: 35947691
DOI: 10.1093/nar/gkac647

Experimental method

X-RAY DIFFRACTION (1.4 Å)