Herpes simplex virus type 1 single-strand DNA binding protein ICP8 enhances the nuclease activity of the UL12 alkaline nuclease by increasing its processivity.
UL12 is a 5'- to 3'-exonuclease encoded by herpes simplex virus type 1 (HSV-1) which degrades single- and double-stranded DNA. UL12 and the single-strand DNA binding protein ICP8 mediate a strand exchange reaction. We found that ICP8 inhibited UL12 digestion of single-stranded DNA but stimulated digestion of double-stranded DNA threefold. The stimulatory effect of ICP8 was independent of a strand exchange reaction; furthermore, the effect was specific to ICP8, as it could not be reproduced by Escherichia coli single-stranded DNA binding protein. The effect of ICP8 on the rate of UL12 double-stranded DNA digestion is attributable to an increase in processivity in the presence of ICP8.
Reuven
Nina Bacher
NB
Department of Molecular, Microbial, and Structural Biology, University of Connecticut Health Center, Farmington, CT 06030-3205, USA.
Weller
Sandra K
SK
D004247:DNA / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000502:physiology*; D012260:Ribonucleases / Q000378:metabolism*; D014764:Viral Proteins / Q000502:physiology*
D004268:DNA-Binding Proteins; C045462:ICP8 protein, Simplexvirus; D014764:Viral Proteins; D004247:DNA; D012260:Ribonucleases; C066964:viral alkaline nuclease