Crystallization and preliminary X-ray crystallographic studies of a PduO-type ATP:cob(I)alamin adenosyltransferase from Bacillus cereus.

Cobalamin adenosyltransferases transfer a 5'-deoxyadenosyl moiety from ATP and covalently attach it to the cobalt(I) ion of the corrin ring of cobalamin to generate adenosylcobalamin. The PduO-type adenosyltransferase from Bacillus cereus was overexpressed in Escherichia coli, purified and crystallized as the apoenzyme as well as in complex with Mg(2+) and ATP (MgATP). Diffraction data were collected to 1.9 A resolution for the native crystals and 2.0 A resolution for the complexed crystals. Both crystals belonged to the orthorhombic space group C222(1); the native crystals have unit-cell parameters a = 64.93, b = 137.08, c = 158.55 A. The asymmetric unit contained one trimer, with a corresponding V(M) of 2.69 A(3) Da(-1).