This old version of Proteopedia is provided for student assignments while the new version is undergoing repairs. Content and edits done in this old version of Proteopedia after March 1, 2026 will eventually be lost when it is retired in about June of 2026.
Apply for new accounts at the new Proteopedia. Your logins will work in both the old and new versions.
2flc
From Proteopedia
| Line 1: | Line 1: | ||
[[Image:2flc.gif|left|200px]] | [[Image:2flc.gif|left|200px]] | ||
| - | + | <!-- | |
| - | + | The line below this paragraph, containing "STRUCTURE_2flc", creates the "Structure Box" on the page. | |
| - | + | You may change the PDB parameter (which sets the PDB file loaded into the applet) | |
| - | + | or the SCENE parameter (which sets the initial scene displayed when the page is loaded), | |
| - | + | or leave the SCENE parameter empty for the default display. | |
| - | | | + | --> |
| - | | | + | {{STRUCTURE_2flc| PDB=2flc | SCENE= }} |
| - | + | ||
| - | + | ||
| - | }} | + | |
'''Post-Reactive Complex of Restriction Endonuclease HinP1I with Nicked Cognate DNA and Magnesium Ions''' | '''Post-Reactive Complex of Restriction Endonuclease HinP1I with Nicked Cognate DNA and Magnesium Ions''' | ||
| Line 27: | Line 24: | ||
[[Category: Type II site-specific deoxyribonuclease]] | [[Category: Type II site-specific deoxyribonuclease]] | ||
[[Category: Horton, J R.]] | [[Category: Horton, J R.]] | ||
| - | [[Category: | + | [[Category: Dna superhelix]] |
| - | [[Category: | + | [[Category: Nicked dna]] |
| - | [[Category: | + | [[Category: Protein dimerizaton]] |
| - | [[Category: | + | [[Category: Protein-dna-metal ion complex]] |
| - | [[Category: | + | [[Category: Restriction endonuclease]] |
| - | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Sun May 4 04:01:43 2008'' | |
| - | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on | + | |
Revision as of 01:01, 4 May 2008
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. 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 Sun May 4 04:01:43 2008
