title: Restriction endonuclease MvaI is a monomer that recognizes its target sequence asymmetrically.
abstract: Restriction endonuclease MvaI recognizes the sequence CC/WGG (W stands for A or T, '/' designates the cleavage site) and generates products with single nucleotide 5'-overhangs. The enzyme has been noted for its tolerance towards DNA modifications. Here, we report a biochemical characterization and crystal structures of MvaI in an apo-form and in a complex with target DNA at 1.5 A resolution. Our results show that MvaI is a monomer and recognizes its pseudosymmetric target sequence asymmetrically. The enzyme consists of two lobes. The catalytic lobe anchors the active site residues Glu36, Asp50, Glu55 and Lys57 and contacts the bases from the minor grove side. The recognition lobe mediates all major grove interactions with the bases. The enzyme in the crystal is bound to the strand with T at the center of the recognition sequence. The crystal structure with calcium ions and DNA mimics the prereactive state. MvaI shows structural similarities to BcnI, which cleaves the related sequence CC/SGG and to MutH enzyme, which is a component of the DNA repair machinery, and nicks one DNA strand instead of making a double-strand break.
authors.affiliation: International Institute of Molecular and Cell Biology, Warsaw, Poland.
authors.forename: Magdalena
authors.initials: M
authors.lastname: Kaus-Drobek
authors.forename: Honorata
authors.initials: H
authors.lastname: Czapinska
authors.forename: Monika
authors.initials: M
authors.lastname: Sokołowska
authors.forename: Gintautas
authors.initials: G
authors.lastname: Tamulaitis
authors.forename: Roman H
authors.initials: RH
authors.lastname: Szczepanowski
authors.forename: Claus
authors.initials: C
authors.lastname: Urbanke
authors.forename: Virginijus
authors.initials: V
authors.lastname: Siksnys
authors.forename: Matthias
authors.initials: M
authors.lastname: Bochtler
mesh_terms: D001483:Base Sequence; D020134:Catalytic Domain; D002850:Chromatography, Gel; D018360:Crystallography, X-Ray; D004247:DNA / Q000737:chemistry / Q000378:metabolism; D019175:DNA Methylation; D015252:Deoxyribonucleases, Type II Site-Specific / Q000737:chemistry* / Q000378:metabolism; D008958:Models, Molecular; D011485:Protein Binding; D013379:Substrate Specificity; D014461:Ultracentrifugation
chemical_list: D004247:DNA; C046545:CCWGG-specific type II deoxyribonucleases; D015252:Deoxyribonucleases, Type II Site-Specific