6V1W

NMR Structure of C-terminal Domain of phi29 ATPase

Summary for 6V1W

• Entry DOI: 10.2210/pdb6v1w/pdb
• NMR Information: BMRB: 30691
• Descriptor: DNA packaging protein (1 entity in total)
• Functional Keywords: viral packaging motor, terminase, rnase h fold, viral protein
• Biological source: Bacillus phage phi29
• Total number of polymer chains: 1
• Total formula weight: 14195.17

Authors

Mahler, B.,Mao, H.,Morais, M.C. (deposition date: 2019-11-21, release date: 2020-09-30, Last modification date: 2024-05-15)

Primary citation

Mahler, B.P.,Bujalowski, P.J.,Mao, H.,Dill, E.A.,Jardine, P.J.,Choi, K.H.,Morais, M.C.
NMR structure of a vestigial nuclease provides insight into the evolution of functional transitions in viral dsDNA packaging motors.
Nucleic Acids Res., 48:11737-11749, 2020

PubMed Abstract: Double-stranded DNA viruses use ATP-powered molecular motors to package their genomic DNA. To ensure efficient genome encapsidation, these motors regulate functional transitions between initiation, translocation, and termination modes. Here, we report structural and biophysical analyses of the C-terminal domain of the bacteriophage phi29 ATPase (CTD) that suggest a structural basis for these functional transitions. Sedimentation experiments show that the inter-domain linker in the full-length protein promotes oligomerization and thus may play a role in assembly of the functional motor. The NMR solution structure of the CTD indicates it is a vestigial nuclease domain that likely evolved from conserved nuclease domains in phage terminases. Despite the loss of nuclease activity, fluorescence binding assays confirm the CTD retains its DNA binding capabilities and fitting the CTD into cryoEM density of the phi29 motor shows that the CTD directly binds DNA. However, the interacting residues differ from those identified by NMR titration in solution, suggesting that packaging motors undergo conformational changes to transition between initiation, translocation, and termination. Taken together, these results provide insight into the evolution of functional transitions in viral dsDNA packaging motors.

PubMed: 33089330
DOI: 10.1093/nar/gkaa874

Experimental method

SOLUTION NMR