1cr4
From Proteopedia
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CRYSTAL STRUCTURE OF THE HELICASE DOMAIN OF THE GENE 4 PROTEIN OF BACTERIOPHAGE T7: COMPLEX WITH DTDP
Overview
Helicases that unwind DNA at the replication fork are ring-shaped oligomeric enzymes that move along one strand of a DNA duplex and catalyze the displacement of the complementary strand in a reaction that is coupled to nucleotide hydrolysis. The helicase domain of the replicative helicase-primase protein from bacteriophage T7 crystallized as a helical filament that resembles the Escherichia coli RecA protein, an ATP-dependent DNA strand exchange factor. When viewed in projection along the helical axis of the crystals, six protomers of the T7 helicase domain resemble the hexameric rings seen in electron microscopic images of the intact T7 helicase-primase. Nucleotides bind at the interface between pairs of adjacent subunits where an arginine is near the gamma-phosphate of the nucleotide in trans. The bound nucleotide stabilizes the folded conformation of a DNA-binding motif located near the center of the ring. These and other observations suggest how conformational changes are coupled to DNA unwinding activity.
About this Structure
1CR4 is a Single protein structure of sequence from Bacteriophage t7 with and as ligands. Full crystallographic information is available from OCA.
Reference
Crystal structure of the helicase domain from the replicative helicase-primase of bacteriophage T7., Sawaya MR, Guo S, Tabor S, Richardson CC, Ellenberger T, Cell. 1999 Oct 15;99(2):167-77. PMID:10535735
Page seeded by OCA on Thu Feb 21 12:08:52 2008
