Purification of aspartate transcarbamoylase from Pseudomonas syringae

Abstract The aspartate transcarbamoylase (ATCase) from Pseudomonas syringae has been purified. The purified enzyme was shown by SDS-PAGE to give two bands. Unambiguous results from N-terminal sequencing suggested that each band represented a homogeneous polypeptide. The M _r (relative molecular mass) of the polypeptides was estimated to be 47 kDa and 34 kDa. The M _r of the holoenzyme determined by gel filtration and electrophoretic migration in polyacrylamide gradient gels under non-denaturing conditions was estimated at approximately 490 kDa. These findings suggest a subunit structure different from any previously described for a bacterial ATCase.