2va8

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spinqualitylabelsall models 2va8, resolution 2.30Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image

DNA REPAIR HELICASE HEL308

Overview

Hel308 is a superfamily 2 helicase conserved in eukaryotes and archaea. It, is thought to function in the early stages of recombination following, replication fork arrest, and has a specificity for removal of the lagging, strand in model replication forks. A homologous helicase constitutes the, N-terminal domain of human DNA polymerase Q. The Drosophila homologue, mus301 is implicated in double strand break repair and meiotic, recombination. We have solved the high-resolution crystal structure of, Hel308 from the crenarchaeon Sulfolobus solfataricus, revealing a, five-domain structure with a central pore lined with essential DNA binding, residues. The fifth domain is shown to act as an autoinhibitory domain or, molecular brake, clamping the ssDNA extruded through the central pore of, the helicase structure to limit the enzyme's helicase activity. This, provides an elegant mechanism to tune the enzyme's processivity to its, functional role. Hel308 can displace streptavidin from a biotinylated DNA, molecule, and this activity is only partially inhibited when the DNA is, pre-bound with abundant DNA binding proteins RPA or Alba1, whilst, pre-binding with the recombinase RadA has no effect on activity. These, data suggest that one function of the enzyme may be in the removal of, bound proteins at stalled replication forks and recombination, intermediates.

About this Structure

2VA8 is a Single protein structure of sequence from Sulfolobus solfataricus with as ligand. Known structural/functional Sites: , , , , , and . Full crystallographic information is available from OCA.

Reference

Structure of the DNA repair helicase HEL308 reveals DNA binding and autoinhibitory domains., Richards JD, Johnson KA, Liu H, McRobbie AM, McMahon S, Oke M, Carter L, Naismith JH, White MF, J Biol Chem. 2007 Dec 4;. PMID:18056710

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