Open AccessCrystallization and preliminary crystallographic analysis of the type IIL restriction enzyme Mme I in complex with DNA
Author(s) -
Callahan Scott J.,
Morgan Richard D.,
Jain Rinku,
Townson Sharon A.,
Wilson Geoffrey G.,
Roberts Richard J.,
Aggarwal Aneel K.
Publication year - 2011
Publication title -
acta crystallographica section f
Language(s) - English
Resource type - Journals
ISSN - 1744-3091
DOI - 10.1107/s1744309111028041
Subject(s) - dna , restriction enzyme , enzyme , biochemistry , biology , binding site , chemistry , crystallography , stereochemistry , microbiology and biotechnology
Type IIL restriction enzymes have rejuvenated the search for user‐specified DNA binding and cutting. By aligning and contrasting the highly comparable amino‐acid sequences yet diverse recognition specificities across the family of enzymes, amino acids involved in DNA binding have been identified and mutated to produce alternative binding specificities. To date, the specificity of Mme I (a type IIL restriction enzyme) has successfully been altered at positions 3, 4 and 6 of the asymmetric TCCRAC (where R is a purine) DNA‐recognition sequence. To further understand the structural basis of Mme I DNA‐binding specificity, the enzyme has been crystallized in complex with its DNA substrate. The crystal belonged to space group P 1, with unit‐cell parameters a = 61.73, b = 94.96, c = 161.24 Å, α = 72.79, β = 89.12, γ = 71.68°, and diffracted to 2.6 Å resolution when exposed to synchrotron radiation. The structure promises to reveal the basis of Mme I DNA‐binding specificity and will complement efforts to create enzymes with novel specificities.