1ynm
Crystal structure of restriction endonuclease HinP1I
| |||||||
| , resolution 2.65Å | |||||||
|---|---|---|---|---|---|---|---|
| Gene: | hinP1IR (Haemophilus influenzae) | ||||||
| Activity: | Type II site-specific deoxyribonuclease, with EC number 3.1.21.4 | ||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||
OverviewOverview
HinP1I, a type II restriction endonuclease, recognizes and cleaves a palindromic tetranucleotide sequence (G/CGC) in double-stranded DNA, producing 2 nt 5' overhanging ends. Here, we report the structure of HinP1I crystallized as one protein monomer in the crystallographic asymmetric unit. HinP1I displays an elongated shape, with a conserved catalytic core domain containing an active-site motif of SDX18QXK and a putative DNA-binding domain. Without significant sequence homology, HinP1I displays striking structural similarity to MspI, an endonuclease that cleaves a similar palindromic DNA sequence (C/CGG) and binds to that sequence crystallographically as a monomer. Almost all the structural elements of MspI can be matched in HinP1I, including both the DNA recognition and catalytic elements. Examining the protein-protein interactions in the crystal lattice, HinP1I could be dimerized through two helices located on the opposite side of the protein to the active site, generating a molecule with two active sites and two DNA-binding surfaces opposite one another on the outer surfaces of the dimer. A possible functional link between this unusual dimerization mode and the tetrameric restriction enzymes is discussed.
About this StructureAbout this Structure
1YNM is a Single protein structure of sequence from Haemophilus influenzae. Full crystallographic information is available from OCA.
ReferenceReference
Structure of HinP1I endonuclease reveals a striking similarity to the monomeric restriction enzyme MspI., Yang Z, Horton JR, Maunus R, Wilson GG, Roberts RJ, Cheng X, Nucleic Acids Res. 2005 Apr 1;33(6):1892-901. Print 2005. PMID:15805123
Page seeded by OCA on Thu Mar 20 15:25:11 2008