1. The acidic C-terminus of vaccinia virus I3 single-strand binding protein promotes proper assembly of DNA–protein complexes
- Author
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David H. Evans, Megan A. Desaulniers, Melissa Harrison, and Ryan S. Noyce
- Subjects
DNA Replication ,Gene Expression Regulation, Viral ,0301 basic medicine ,HMG-box ,Amino Acid Motifs ,Vaccinia virus ,Biology ,Single-stranded binding protein ,Viral Proteins ,03 medical and health sciences ,Replication factor C ,SeqA protein domain ,Virology ,Vaccinia ,Humans ,Single-strand DNA binding protein ,Replication protein A ,Single-strand DNA-binding protein ,Molluscum contagiosum virus ,Ter protein ,DNA replication ,Molecular biology ,DNA-Binding Proteins ,030104 developmental biology ,DNA, Viral ,biology.protein ,I3L - Abstract
The vaccinia virus I3L gene encodes a single-stranded DNA binding protein (SSB) that is essential for virus DNA replication and is conserved in all Chordopoxviruses. The I3 protein contains a negatively charged C-terminal tail that is a common feature of SSBs. Such acidic tails are critical for SSB-dependent replication, recombination and repair. We cloned and purified variants of the I3 protein, along with a homolog from molluscum contagiosum virus, and tested how the acidic tail affected DNA–protein interactions. Deleting the C terminus of I3 enhanced the affinity for single-stranded DNA cellulose and gel shift analyses showed that it also altered the migration of I3-DNA complexes in agarose gels. Microinjecting an antibody against I3 into vaccinia-infected cells also selectively inhibited virus replication. We suggest that this domain promotes cooperative binding of I3 to DNA in a way that would maintain an open DNA configuration around a replication site.
- Published
- 2016
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