Crystallization and preliminary X-ray analysis of a bifunctional enzyme: HHDD isomerase/OPET decarboxylase from Escherichia coli.
A bifunctional enzyme, 2-hydroxyhepta-2,4,-diene-l,7-dioate isomerase/5-oxopent-3-ene-1,2,5-tricarboxylate decarboxylase from the homoprotocatechaute (HPC) degradative pathway of Escherichia coli has been crystallized, using polyethylene glycol as a precipitant. The enzyme, of molecular weight 44 514 Da forms crystals belonging to the orthorhombic space group P2(1)2(1)2(1) with cell dimensions a = 106, b = 127 and c = 139 A. The crystals diffract to at least 2.2 A resolution using synchrotron radiation. A complete native data set has been collected to 3.3 A resolution. The Matthews number calculated for a single molecule in the asymmetric unit is outside the normally acceptable limits and the aggregation state of the molecules in the crystal was investigated using self-rotation function studies, the results show features which are consistent with a tetramer in the asymmetric unit, giving a V(m) value of 2.7 A(3) Da(-1).
Jervis
T J
TJ
Physics Department, Keele University, Staffordshire, England.
Roper
D I
DI
Glover
I D
ID