title: Crystallization and preliminary crystallographic studies of a bifunctional restriction endonuclease Eco57I.
abstract: Restriction endonuclease Eco57I from Escherichia coli recognizes asymmetric DNA sequence 5'-CTGAAG and has both restriction (DNA cleavage a short distance away from the recognition site) and modification (methylation) activities residing in a single polypeptide chain. Single crystals of wild-type Eco57I ternary complexes with double-stranded DNA and sinefungin, a stimulator of endonuclease activity, were obtained by the vapor diffusion technique and characterized crystallographically for different variants of the DNA component. The best data for the complex with 25-mer DNA were collected to 4.2-A resolution at 100 K using synchrotron radiation. The crystals are orthorhombic, space group P2(1)2(1)2, with a=164.3, b=293.0, c=71.1 A, and contain two to four copies of the protein in the asymmetric unit.
authors.affiliation: Institute of Biotechnology, Graiciuno 8, LT2028 Vilnius, Lithuania. eigie@ibt.lt
authors.forename: Giedre
authors.initials: G
authors.lastname: Tamulaitiene
authors.forename: Saulius
authors.initials: S
authors.lastname: Grazulis
authors.forename: Arvydas
authors.initials: A
authors.lastname: Janulaitis
authors.forename: Robert
authors.initials: R
authors.lastname: Janowski
authors.forename: Grzegorz
authors.initials: G
authors.lastname: Bujacz
authors.forename: Mariusz
authors.initials: M
authors.lastname: Jaskolski
mesh_terms: D000241:Adenosine / Q000031:analogs & derivatives* / Q000378:metabolism; D003460:Crystallization; D018360:Crystallography, X-Ray; D004247:DNA / Q000378:metabolism; D004262:DNA Restriction Enzymes / Q000737:chemistry* / Q000378:metabolism; D004926:Escherichia coli / Q000737:chemistry / Q000201:enzymology / Q000378:metabolism; D015265:Site-Specific DNA-Methyltransferase (Adenine-Specific) / Q000737:chemistry* / Q000378:metabolism
chemical_list: D004247:DNA; C059642:DNA modification methylase Eco57I; D015265:Site-Specific DNA-Methyltransferase (Adenine-Specific); D004262:DNA Restriction Enzymes; C054219:endodeoxyribonuclease Eco57I; D000241:Adenosine; C006235:sinefungin