Involved in the biosynthesis of the phytotoxin coronatine (COR) which mimics the plant hormone jasmonic acid isoleucine and promotes opening of stomata for bacterial entry, bacterial growth in the apoplast, systemic susceptibility, and disease symptoms. CmaA catalyzes the adenylation of L-allo-isoleucine (via the A domain) and the attachment of L-allo-isoleucine to the 4'-phosphopantetheine arm located within the T domain of CmaA. It can also use L-isoleucine, L-leucine and L-valine as substrates. ATP + holo-[CmaA peptidyl-carrier protein] + L-alloisoleucine = AMP + diphosphate + L-alloisoleucyl-[CmaA peptidyl-carrier protein] Binds 1 phosphopantetheine covalently. kcat is 17 min(-1) for ligase activity with L-allo-isoleucine as substrate (at pH 7.5 and 25 degrees Celsius). kcat is 16 min(-1) for ligase activity with L-leucine as substrate (at pH 7.5 and 25 degrees Celsius). kcat is 12 min(-1) for ligase activity with L-valine as substrate (at pH 7.5 and 25 degrees Celsius). kcat is 6.7 min(-1) for ligase activity with DL-coronamic acid as substrate (at pH 7.5 and 25 degrees Celsius). kcat is 2.8 min(-1) for ligase activity with L-isoleucine as substrate (at pH 7.5 and 25 degrees Celsius). kcat is 1.1 min(-1) for ligase activity with D-isoleucine and DL-norcoronamic acid as substrates (at pH 7.5 and 25 degrees Celsius). kcat is 0.2 min(-1) for ligase activity with D-allo-isoleucine as substrate (at pH 7.5 and 25 degrees Celsius). Homodimer. The didomain protein contains an adenylation domain (A domain) and a thiolation domain (T domain). Belongs to the ATP-dependent AMP-binding enzyme family.