Involved in the biosynthesis of the beta-lactamase inhibitor, clavulanic acid. Catalyzes the thiamine diphosphate (ThDP) dependent condensation of D-glyceraldehyde-3-phosphate (D-G3P) with L-arginine to yield the beta-amino acid, N2-(2-carboxyethyl)arginine (CEA) via a beta-elimination resulting in the formation of an enol which undergoes a second elimination to generate the alpha,beta-unsaturated acryloyl-ThDP. D-glyceraldehyde 3-phosphate + L-arginine = H(+) + N(2)-(2-carboxyethyl)-L-arginine + phosphate Binds 1 Mg(2+) ion per subunit. Binds 1 thiamine pyrophosphate per subunit. Homotetramer; dimer of dimers. Belongs to the TPP enzyme family.