3pjr | pdb_00003pjr

HELICASE SUBSTRATE COMPLEX

spinqualitylabelsall models 3pjr, resolution 3.30Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 3pjr is a 3 chain structure with sequence from Atcc 12980. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Ligands: ATP Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function [PCRA_GEOSE] DNA helicase. Has a broad nucleotide specificity, even being able to hydrolyze ethenonucleotides, and is able to couple the hydrolysis to unwinding of DNA substrates. It is a 3'-5' helicase but at high protein concentrations it can also displace a substrate with a 5' tail. Preferred substrate being one with both single and double-stranded regions of DNA. 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 PubMed We have determined two different structures of PcrA DNA helicase complexed with the same single strand tailed DNA duplex, providing snapshots of different steps on the catalytic pathway. One of the structures is of a complex with a nonhydrolyzable analog of ATP and is thus a "substrate" complex. The other structure contains a bound sulphate ion that sits in a position equivalent to that occupied by the phosphate ion produced after ATP hydrolysis, thereby mimicking a "product" complex. In both complexes, the protein is monomeric. Large and distinct conformational changes occur on binding DNA and the nucleotide cofactor. Taken together, these structures provide evidence against an "active rolling" model for helicase action but are instead consistent with an "inchworm" mechanism. Crystal structures of complexes of PcrA DNA helicase with a DNA substrate indicate an inchworm mechanism.,Velankar SS, Soultanas P, Dillingham MS, Subramanya HS, Wigley DB Cell. 1999 Apr 2;97(1):75-84. PMID:10199404 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Helicase Molecular Playground/PcrA Helicase PcrA helicase

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