Structure of HinP1I endonuclease reveals a striking similarity to the monomeric restriction enzyme MspI

• Type of Material: Article
• Authors: Zhe Yang, Emory University; John Horton, Emory University; Robert Maunus, Emory University; Geoffrey G. Wilson, Emory University; Richard J. Roberts, Emory University; Xiaodong Cheng, Emory University
• Language: English
• Date: 2005
• Publisher: Oxford University Press (OUP)
• Publication Version: Final Published Version
• Copyright Statement: © The Author 2005. Published by Oxford University Press. All rights reserved The online version of this article has been published under an open access model. Users are entitled to use, reproduce, disseminate, or display the open access version of this article for non-commercial purposes provided that: the original authorship is properly and fully attributed; the Journal and Oxford University Press are attributed as the original place of publication with the correct citation details given; if an article is subsequently reproduced or disseminated not in its entirety but only in part or as a derivative work this must be clearly indicated. For commercial re-use, please contact [e-mail]
• Final Published Version (URL): http://nar.oxfordjournals.org/content/33/6/1892
• Title of Journal or Parent Work: Nucleic Acids Research
• ISSN: 0305-1048
• Volume: 33
• Issue: 6
• Start Page: 1892
• End Page: 1901
• Grant/Funding Information: Financial support for the beamlines comes principally from the Offices of Biological and Environmental Research and of Basic Energy Sciences of the US Department of Energy, and from the National Center for Research Resources of the National Institutes of Health.; Funding to pay the Open Access publication charges for this article was provided by New England Biolabs.; The study was partly supported by US Public Health Service grant GM49245 (X.C., Z.Y. and J.R.H.) and New England Biolabs (R.J.R., R.M. and G.G.W.).
• Research Categories: Chemistry, Biochemistry; Health Sciences, General

Abstract

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.