7JQ7

The Phi-28 gp11 DNA packaging Motor

Summary for 7JQ7

• Entry DOI: 10.2210/pdb7jq7/pdb
• Related: 7JQ6
• Descriptor: Encapsidation protein, IODIDE ION, SULFATE ION, ... (4 entities in total)
• Functional Keywords: atpase, dna packaging, motor, phage, asce fold, viral protein
• Biological source: Lactococcus phage asccphi28
• Total number of polymer chains: 5
• Total formula weight: 242165.83

Authors

Morais, M.C.,White, M.A.,Dill, E. (deposition date: 2020-08-10, release date: 2021-06-16, Last modification date: 2024-11-20)

Primary citation

Pajak, J.,Dill, E.,Reyes-Aldrete, E.,White, M.A.,Kelch, B.A.,Jardine, P.J.,Arya, G.,Morais, M.C.
Atomistic basis of force generation, translocation, and coordination in a viral genome packaging motor.
Nucleic Acids Res., 49:6474-6488, 2021

PubMed Abstract: Double-stranded DNA viruses package their genomes into pre-assembled capsids using virally-encoded ASCE ATPase ring motors. We present the first atomic-resolution crystal structure of a multimeric ring form of a viral dsDNA packaging motor, the ATPase of the asccφ28 phage, and characterize its atomic-level dynamics via long timescale molecular dynamics simulations. Based on these results, and previous single-molecule data and cryo-EM reconstruction of the homologous φ29 motor, we propose an overall packaging model that is driven by helical-to-planar transitions of the ring motor. These transitions are coordinated by inter-subunit interactions that regulate catalytic and force-generating events. Stepwise ATP binding to individual subunits increase their affinity for the helical DNA phosphate backbone, resulting in distortion away from the planar ring towards a helical configuration, inducing mechanical strain. Subsequent sequential hydrolysis events alleviate the accumulated mechanical strain, allowing a stepwise return of the motor to the planar conformation, translocating DNA in the process. This type of helical-to-planar mechanism could serve as a general framework for ring ATPases.

PubMed: 34050764
DOI: 10.1093/nar/gkab372

Experimental method

X-RAY DIFFRACTION (2.895 Å)