Pyruvate-formate-lyase-deactivase and acetyl-CoA reductase activities of Escherichia coli reside on a polymeric protein particle encoded by adhE.

A 4.8 kb DNA-fragment was cloned and sequenced encompassing the structural gene of PFL-deactivase (2.7 kb) and 2 kb of the 5' flanking region that contains the elements for anaerobic induction. A mutant lacking deactivase was shown to require exogenous electron acceptors for anaerobic growth with glucose. This revealed the identity of PFL-deactivase with the alcohol and acetaldehyde dehydrogenases of E. coli. The multienzyme represents a homopolymeric protein (approximately 40 x 96 kDa) requiring Fe2+ for all functions.