2p6u
From Proteopedia
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Apo structure of the Hel308 superfamily 2 helicase
Overview
To reveal the mechanism of processive strand separation by superfamily-2, (SF2) 3'-->5' helicases, we determined apo and DNA-bound crystal, structures of archaeal Hel308, a helicase that unwinds lagging strands and, is related to human DNA polymerase theta. Our structure captures the, duplex-unwinding reaction, shows that initial strand separation does not, require ATP and identifies a prominent beta-hairpin loop as the unwinding, element. Similar loops in hepatitis C virus NS3 helicase and RNA-decay, factors support the idea that this duplex-unwinding mechanism is, applicable to a broad subset of SF2 helicases. Comparison with ATP-bound, SF2 enzymes suggests that ATP promotes processive unwinding of 1 base pair, by ratchet-like transport of the 3' product strand. Our results provide a, first structural framework for strand separation by processive SF2 3'-->5', helicases and reveal important mechanistic differences from SF1 helicases.
About this Structure
2P6U is a Protein complex structure of sequences from Archaeoglobus fulgidus with as ligand. Full crystallographic information is available from OCA.
Reference
Structural basis for DNA duplex separation by a superfamily-2 helicase., Buttner K, Nehring S, Hopfner KP, Nat Struct Mol Biol. 2007 Jul;14(7):647-52. Epub 2007 Jun 10. PMID:17558417
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