1ynm

[[Image:1ynm.gif|left|200px]]<br /><applet load="1ynm" size="450" color="white" frame="true" align="right" spinBox="true"

caption="1ynm, resolution 2.65&Aring;" />

'''Crystal structure of restriction endonuclease HinP1I'''<br />

==Overview==

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 Structure==

1YNM is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Haemophilus_influenzae Haemophilus influenzae]. Active as [http://en.wikipedia.org/wiki/Type_II_site-specific_deoxyribonuclease Type II site-specific deoxyribonuclease], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.1.21.4 3.1.21.4] Full crystallographic information is available from [http://ispc.weizmann.ac.il/oca-bin/ocashort?id=1YNM OCA].

 

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:[http://ispc.weizmann.ac.il//pmbin/getpm?pmid=15805123 15805123]

[[Category: Single protein]]

[[Category: Type II site-specific deoxyribonuclease]]

[[Category: Cheng, X.]]

[[Category: Horton, J.R.]]

[[Category: Maunus, R.]]

[[Category: Roberts, R.J.]]

[[Category: Wilson, G.G.]]

[[Category: Yang, Z.]]