A superfamily 3 DNA helicase encoded by plasmid pSSVi from the hyperthermophilic archaeon Sulfolobus solfataricus unwinds DNA as a higher-order oligomer and interacts with host primase.

ABSTRACT: Replication proteins encoded by nonconjugative plasmids from the hyperthermophilic archaea of the order Sulfolobales show great diversity in amino acid sequence. We have biochemically characterized ORF735, a replication protein from pSSVi, an integrative nonconjugative plasmid from Sulfolobus solfataricus P2. We show that ORF735 is a DNA helicase of superfamily 3. It unwound double-stranded DNA (dsDNA) in a 3'-to-5' direction in the presence of ATP over a wide range of temperatures, from 37 degrees C to 75 degrees C, and possessed DNA-stimulated ATPase activity. ORF735 existed in solution as a salt-stable dimer and was capable of assembling into a salt-sensitive oligomer that was significantly larger than a hexamer in the presence of a divalent cation (Mg(2+)) and an adenine nucleotide (AT

SUBMITTER: Guo X 

PROVIDER: S-EPMC2838049 | biostudies-literature | 2010 Apr

REPOSITORIES: biostudies-literature