A DNA-binding activity in BPV initiator protein E1 required for melting duplex ori DNA but not processive helicase activity initiated on partially single-stranded DNA.

ABSTRACT: The papillomavirus replication protein E1 assembles on the viral origin of replication (ori) as a series of complexes. It has been proposed that the ori DNA is first melted by a head-to-tail double trimer of E1 that evolves into two hexamers that encircle and unwind DNA bi-directionally. Here the role of a conserved lysine residue in the smaller tier or collar of the E1 helicase domain in ori processing is described. Unlike the residues of the AAA+ domain DNA-binding segments (beta-hairpin and hydrophobic loop; larger tier), this residue functions in the initial melting of duplex ori DNA but not in the processive DNA unwinding of partially single-stranded test substrates. These data therefore define a new DNA-binding related activity in the E1 protein and demonstrate that separate function

SUBMITTER: Sanders CM 

PROVIDER: S-EPMC2330243 | biostudies-literature | 2008 Apr

REPOSITORIES: biostudies-literature