2P6R

Crystal structure of superfamily 2 helicase Hel308 in complex with unwound DNA

Summary for 2P6R

• Entry DOI: 10.2210/pdb2p6r/pdb
• Descriptor: 25-MER, 5'-D(*CP*TP*AP*GP*AP*GP*AP*CP*TP*AP*TP*CP*GP*AP*T)-3', afUHEL308 HELICASE (3 entities in total)
• Functional Keywords: protein-dna complex, sf2 helicase, archaeal helicase, dna repair, dna binding protein-dna complex, dna binding protein/dna
• Biological source: Archaeoglobus fulgidus
• Total number of polymer chains: 3
• Total formula weight: 91373.78

Authors

Buettner, K.,Nehring, S.,Hopfner, K.P. (deposition date: 2007-03-19, release date: 2007-06-12, Last modification date: 2024-02-21)

Primary citation

Buttner, K.,Nehring, S.,Hopfner, K.P.
Structural basis for DNA duplex separation by a superfamily-2 helicase.
Nat.Struct.Mol.Biol., 14:647-652, 2007

PubMed Abstract: 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.

PubMed: 17558417
DOI: 10.1038/nsmb1246

Experimental method

X-RAY DIFFRACTION (3 Å)