(from Interpro) Carboxymethylenebutenolidase (CMBL) is a human homologue of Pseudomonas dienelactone hydrolase involved in the bacterial halocatechol degradation pathway. It is a cysteine hydrolase that can convert the prodrug olmesartan medoxomil into its pharmacologically active metabolite olmerstatan, an angiotensin receptor blocker, in liver and intestine. May also activate beta-lactam antibiotics faropenem medoxomil and lenampicillin. Not inhibited by DFP, PMSF, eserine or EDTA. Strongly inhibited by p-chloromercuribenzoate (PCMB). This entry also includes uncharacterised DLH domain-containing proteins from plants. This family was previously included in Dienelactone_hydrolase