Purification, crystallization and preliminary X-ray analysis of the M.BseCI DNA methyltransferase from Bacillus stearothermophilus

The DNA methyltransferase M.BseC1 from B. stearothermophilus methylates the N6 atom of the 3′ adenine in the sequence 5′-ATCGAT-3′. The 579-residue protein has been isolated and crystallized using seeding and microdialysis techniques. The crystals are monoclinic, space group P2₁ with cell dimensions a = 53.7, b = 85.7, c = 151.8 Å and β = 95.1°, two molecules in the asymmetric unit and diffract to at least 2.5 Å resolution.