Characterization of the first homomeric multidomain acetyl-CoA carboxylase from Saccharopolyspora erythraea

LIVIERI, ANDREA L.; EDUARDO RODRIGUEZ; GRAMAJO H; LAURA NAVONE

Paraná, Entre Ríos

Congreso; LIV Reunión Anual Sociedad Argentina de Investigación en Bioquímica y Biología Molecular (SAIB); 2018

SAIB

Acetyl-CoA carboxylases (ACCs) catalyze the biotin dependent carboxylation of acetyl-CoA to give malonyl-CoA, a key extender unit for thecommitted step of the de novo fatty acids biosynthesis and polyketide natural products in actinobacteria. ACCs are composed by three maincatalytic domains and few non-catalytic domains. In Prokaryotes and plastids of most plants, these domains are encoded by separate subunits,establishing heteromerics complexes. However, cytosolic ACCs of Eukaryotes and the ones from plastids of graminaceous monocots areencoded by a single polypeptide, establishing homomericmultisubunit complexes. To date there are no description of any homomericmultidomain ACC from bacteria. Recently, bioinformatics analysis allowed us to identifysace_4237gene ofSaccharopolysporaerythraeaas aputative homomeric multidomain ACC. We were able to purify the protein by recombinant expression, obtaining an active homomeric enzymeas described for most eukaryotic ACCs. Kinetic studies have demonstrated its in vitro activity as ACC as well as propionil-CoA carboxylase. Inaddition, the construction of a conditional mutant allowed us to study the physiological role of SACE_4237. Growth of the conditional mutantwas dependent of SACE_4237 expression or oleic acid supplementation to the media. All together, these results demonstrate that SACE_4237 isthe first homomeric multidomain acyl-CoA carboxylase described from bacteria which main role is provide malonyl-CoA for the novo fatty acidbiosynthesis inS. erythraea.