Structure of D-glyceraldehyde-3-phosphate dehydrogenase fromPalinurus versicolor in a tetragonal crystal form

D-glyceraldehyde-3-phosphate dehydrogenase (holo-GAPDH) fromPalinurus versicolor was crystallized in a novel crystal form by the method of sitting-drop vapor diffusion. The crystals have space groupP42₁2, cell parameters a=15.49 nm, c=8.03 nm and two subunits per asymmetric unit. The crystal structure at 0.34 nm was determined by the molecular replacement method. The final model has crystallographicR _free andR factors of 0.274 and 0.262, and r.m.s. deviations of 0.002 nm for bond lengths and 2.33° for bond angles. The two subunits in asymmetric unit are similar to each other not only in the three-dimensional structure, but also in average temperature factors. This result demonstrates that the obvious difference in average temperature factors for the different subunits in C2 crystal form reported previously may be attributed to the different crystallographic environments of the subunits. This further supports that holo-GAPDH has a good 222 molecular symmetry.