Binding and unwinding: SF3 viral helicases.
The SF3 helicases, distinct from the more prevalent SF1 and SF2 helicases, were originally identified in the genomes of small DNA and RNA viruses. The first crystal structures of SF3 helicases have been determined, revealing a closer structural relationship to AAA+ proteins than to RecA, consistent with their participation in replication initiation. In conjunction with origin-binding domains, SF3 helicases are responsible for distorting DNA before replication forks can be assembled. At these forks, the SF3 helicases act as replicative helicases. The simian virus 40 SF3 helicase forms a hexameric ring, anticipated to be characteristic of the entire superfamily.
Hickman
Alison Burgess
AB
Laboratory of Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, 5 Center Drive MSC 0560, Bethesda, MD 20892-0560, USA.
Dyda
Fred
F
D001665:Binding Sites; D004265:DNA Helicases / Q000737:chemistry* / Q000378:metabolism*; D004261:DNA Replication; D004279:DNA, Viral / Q000737:chemistry* / Q000378:metabolism; D016679:Genome, Viral; D011485:Protein Binding; D011487:Protein Conformation; D020365:RNA Helicases / Q000737:chemistry* / Q000378:metabolism*; D013329:Structure-Activity Relationship; D014779:Virus Replication
D004279:DNA, Viral; D004265:DNA Helicases; D020365:RNA Helicases