2flc
From Proteopedia
(New page: 200px<br /><applet load="2flc" size="350" color="white" frame="true" align="right" spinBox="true" caption="2flc, resolution 2.59Å" /> '''Post-Reactive Comple...) |
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==Overview== | ==Overview== | ||
| - | HinP1I recognizes and cleaves the palindromic tetranucleotide sequence G | + | HinP1I recognizes and cleaves the palindromic tetranucleotide sequence G downward arrowCGC in DNA. We report three structures of HinP1I-DNA complexes: in the presence of Ca(2+) (pre-reactive complex), in the absence of metal ion (binary complex) and in the presence of Mg(2+) (post-reactive complex). HinP1I forms a back-to-back dimer with two active sites and two DNA duplexes bound on the outer surfaces of the dimer facing away from each other. The 10 bp DNA duplexes undergo protein-induced distortions exhibiting features of A-, B- and Z-conformations: bending on one side (by intercalation of a phenylalanine side chain into the major groove), base flipping on the other side of the recognition site (by expanding the step rise distance of the local base pair to Z-form) and a local A-form conformation between the two central C:G base pairs of the recognition site (by binding of the N-terminal helix in the minor groove). In the pre- and post-reactive complexes, two metals (Ca(2+) or Mg(2+)) are found in the active site. The enzyme appears to cleave DNA sequentially, hydrolyzing first one DNA strand, as seen in the post-reactive complex in the crystalline state, and then the other, as supported by the observation that, in solution, a nicked DNA intermediate accumulates before linearization. |
==About this Structure== | ==About this Structure== | ||
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[[Category: Single protein]] | [[Category: Single protein]] | ||
[[Category: Type II site-specific deoxyribonuclease]] | [[Category: Type II site-specific deoxyribonuclease]] | ||
| - | [[Category: Horton, J | + | [[Category: Horton, J R.]] |
[[Category: CL]] | [[Category: CL]] | ||
[[Category: MG]] | [[Category: MG]] | ||
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[[Category: restriction endonuclease]] | [[Category: restriction endonuclease]] | ||
| - | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 17:22:34 2008'' |
Revision as of 15:22, 21 February 2008
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Post-Reactive Complex of Restriction Endonuclease HinP1I with Nicked Cognate DNA and Magnesium Ions
Overview
HinP1I recognizes and cleaves the palindromic tetranucleotide sequence G downward arrowCGC in DNA. We report three structures of HinP1I-DNA complexes: in the presence of Ca(2+) (pre-reactive complex), in the absence of metal ion (binary complex) and in the presence of Mg(2+) (post-reactive complex). HinP1I forms a back-to-back dimer with two active sites and two DNA duplexes bound on the outer surfaces of the dimer facing away from each other. The 10 bp DNA duplexes undergo protein-induced distortions exhibiting features of A-, B- and Z-conformations: bending on one side (by intercalation of a phenylalanine side chain into the major groove), base flipping on the other side of the recognition site (by expanding the step rise distance of the local base pair to Z-form) and a local A-form conformation between the two central C:G base pairs of the recognition site (by binding of the N-terminal helix in the minor groove). In the pre- and post-reactive complexes, two metals (Ca(2+) or Mg(2+)) are found in the active site. The enzyme appears to cleave DNA sequentially, hydrolyzing first one DNA strand, as seen in the post-reactive complex in the crystalline state, and then the other, as supported by the observation that, in solution, a nicked DNA intermediate accumulates before linearization.
About this Structure
2FLC is a Single protein structure of sequence from Haemophilus influenzae with and as ligands. Active as Type II site-specific deoxyribonuclease, with EC number 3.1.21.4 Full crystallographic information is available from OCA.
Reference
DNA nicking by HinP1I endonuclease: bending, base flipping and minor groove expansion., Horton JR, Zhang X, Maunus R, Yang Z, Wilson GG, Roberts RJ, Cheng X, Nucleic Acids Res. 2006 Feb 9;34(3):939-48. Print 2006. PMID:16473850
Page seeded by OCA on Thu Feb 21 17:22:34 2008
