1cr4
From Proteopedia
CRYSTAL STRUCTURE OF THE HELICASE DOMAIN OF THE GENE 4 PROTEIN OF BACTERIOPHAGE T7: COMPLEX WITH DTDP
Structural highlights
Function[PRIM_BPT7] Synthesizes short RNA primers for DNA replication. Unwinds the DNA at the replication forks and generates single-stranded DNA for both leading and lagging strand synthesis. The primase synthesizes short RNA primers on the lagging strand that the polymerase elongates using dNTPs.[1] [2] [3] Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedHelicases 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. 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[4] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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