2gig

Alteration of sequence specificity of the type II restriction endonuclease HINCII through an indirect readout mechanism

spinqualitylabelsall models 2gig, resolution 1.83Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 2gig is a 4 chain structure with sequence from Haemophilus influenzae. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 1.83Å Ligands: NA Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function T2C2_HAEIF Recognizes the double-stranded sequence GTYRAC and cleaves after Y-3. Publication Abstract from PubMed The functional and structural consequences of a mutation of the DNA intercalating residue of HincII, Q138F, are presented. Modeling has suggested that the DNA intercalation by Gln-138 results in DNA distortions potentially used by HincII in indirect readout of its cognate DNA, GTYRAC (Y = C or T, R = A or G) (Horton, N. C., Dorner, L. F., and Perona, J. J. (2002) Nat. Struct. Biol. 9, 42-47). Kinetic data presented here indicate that the mutation of glutamine 138 to phenylalanine (Q138F) results in a change in sequence specificity at the center two base pairs of the cognate recognition site. We show that the preference of HincII for cutting, but not binding, the three cognate sites differing in the center two base pairs has been altered by the mutation Q138F. Five new crystal structures are presented including Q138F HincII bound to GTTAAC and GTCGAC both with and without Ca2+ as well as the structure of wild type HincII bound to GTTAAC. The Q138F HincII/DNA structures show conformational changes in the protein, bound DNA, and at the protein-DNA interface, consistent with the formation of adaptive complexes. Analysis of these structures and the effect of Ca2+ binding on the protein-DNA interface illuminates the origin of the altered specificity by the mutation Q138F in the HincII enzyme. Alteration of sequence specificity of the type II restriction endonuclease HincII through an indirect readout mechanism.,Joshi HK, Etzkorn C, Chatwell L, Bitinaite J, Horton NC J Biol Chem. 2006 Aug 18;281(33):23852-69. Epub 2006 May 4. PMID:16675462 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Endonuclease 3D structures

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