Expression of rat liver S-adenosylmethionine synthetase in Escherichia coli results in two active oligomeric forms

摘要: A cDNA containing the complete coding sequence for rat liver S-adenosylmethionine synthetase was cloned into prokaryotic expression vector pT7-7 and expressed in Escherichia coli BL21(DE3). major additional band corresponding to a protein of 48 kDa detected on SDS/PAGE after induction with isopropyl beta-D-thiogalactopyranoside. This distributed both soluble insoluble fractions accounted approx. 30% total bacterial protein. The enzyme fully active, as revealed by assays vitro activity. In addition, transformed bacteria exhibited highly increased levels intracellular S-adenosylmethionine. Two active forms recombinant enzyme, apparent molecular masses 210 110 kDa, were when cytosolic extracts cells fractionated gel-filtration chromatography. It is concluded that polypeptide assemble tetramers dimers.