3NT7

Crystal Structure of Vaccinia Virus Uracil DNA Glycosylase R187V Mutant

Summary for 3NT7

• Entry DOI: 10.2210/pdb3nt7/pdb
• Related: 2OWQ 2OWR
• Descriptor: Uracil-DNA glycosylase, SULFATE ION, GLYCEROL, ... (4 entities in total)
• Functional Keywords: uracil-dna glycosylase fold, hydrolase
• Biological source: VACCINIA VIRUS WESTERN RESERVE (VACV)
• Total number of polymer chains: 2
• Total formula weight: 54768.40

Authors

Chattopadhyay, D. (deposition date: 2010-07-02, release date: 2011-05-18, Last modification date: 2023-09-06)

Primary citation

Druck Shudofsky, A.M.,Silverman, J.E.,Chattopadhyay, D.,Ricciardi, R.P.
Vaccinia virus D4 mutants defective in processive DNA synthesis retain binding to A20 and DNA.
J.Virol., 84:12325-12335, 2010

PubMed Abstract: Genome replication is inefficient without processivity factors, which tether DNA polymerases to their templates. The vaccinia virus DNA polymerase E9 requires two viral proteins, A20 and D4, for processive DNA synthesis, yet the mechanism of how this tricomplex functions is unknown. This study confirms that these three proteins are necessary and sufficient for processivity, and it focuses on the role of D4, which also functions as a uracil DNA glycosylase (UDG) repair enzyme. A series of D4 mutants was generated to discover which sites are important for processivity. Three point mutants (K126V, K160V, and R187V) which did not function in processive DNA synthesis, though they retained UDG catalytic activity, were identified. The mutants were able to compete with wild-type D4 in processivity assays and retained binding to both A20 and DNA. The crystal structure of R187V was resolved and revealed that the local charge distribution around the substituted residue is altered. However, the mutant protein was shown to have no major structural distortions. This suggests that the positive charges of residues 126, 160, and 187 are required for D4 to function in processive DNA synthesis. Consistent with this is the ability of the conserved mutant K126R to function in processivity. These mutants may help unlock the mechanism by which D4 contributes to processive DNA synthesis.

PubMed: 20861259
DOI: 10.1128/JVI.01435-10

Experimental method

X-RAY DIFFRACTION (2.4 Å)