title: Crystallization and preliminary X-ray diffraction analysis of MspI restriction endonuclease in complex with its cognate DNA.
abstract: The MspI restriction endonuclease is a type II restriction enzyme. Unlike all other restriction enzymes with known structures, MspI recognizes the palindromic tetranucleotide sequence 5'-C/CGG and cleaves it as indicated by the '/' to produce DNA products with 5' two-base overhangs. Owing to the nature of its cleavage pattern, it is likely that MspI would represent a new structural class of restriction endonucleases. Crystals of the dimeric MspI restriction enzyme bound to a duplex DNA molecule containing the specific recognition sequence have been obtained by vapor-diffusion techniques in the presence of polyethylene glycol as precipitant. The crystals belong to the monoclinic space group P2(1), with unit-cell parameters a = 50.2, b = 131.6, c = 59.3 A, beta = 109.7 degrees. The crystals contain one dimeric complex in the asymmetric unit. A complete native data set has been collected to a resolution of 2.05 A by cryo-crystallographic methods, with an R(merge) of 4.0%.
authors.affiliation: Department of Physiology and Structural Biology, Boston University School of Medicine, 715 Albany Street, Boston, MA 02118-2526, USA.
authors.forename: T J
authors.initials: TJ
authors.lastname: O'Loughlin
authors.forename: Q
authors.initials: Q
authors.lastname: Xu
authors.forename: R B
authors.initials: RB
authors.lastname: Kucera
authors.forename: L F
authors.initials: LF
authors.lastname: Dorner
authors.forename: S
authors.initials: S
authors.lastname: Sweeney
authors.forename: I
authors.initials: I
authors.lastname: Schildkraut
authors.forename: H C
authors.initials: HC
authors.lastname: Guo
mesh_terms: D003460:Crystallization; D004247:DNA / Q000737:chemistry*; D019003:Deoxyribonuclease HpaII / Q000737:chemistry* / Q000302:isolation & purification; D009016:Moraxella / Q000201:enzymology; D011487:Protein Conformation; D014961:X-Ray Diffraction
chemical_list: D004247:DNA; D019003:Deoxyribonuclease HpaII