ATP + N(2)-(2-carboxyethyl)-L-arginine = AMP + deoxyamidinoproclavaminate + diphosphate + H(+) Binds 1 Mg(2+) ion per subunit. Antibiotic biosynthesis; clavulanate biosynthesis; clavulanate from D-glyceraldehyde 3-phosphate and L-arginine: step 2/8. Homodimer. Belongs to the asparagine synthetase family.