NAD-dependent lysine deacetylase that specifically removes acetyl groups on target proteins. Also acts as a protein-lysine deacylase by mediating protein desuccinylation and de-2-hydroxyisobutyrylation. Modulates the activities of several proteins which are inactive in their acylated form. Activates the enzyme acetyl-CoA synthetase by deacetylating 'Lys-609' in the inactive, acetylated form of the enzyme. May also modulate the activity of other propionyl-adenosine monophosphate (AMP)-forming enzymes. H2O + N(6)-acetyl-L-lysyl-[protein] + NAD(+) = 2''-O-acetyl-ADP-D-ribose + L-lysyl-[protein] + nicotinamide H2O + N(6)-succinyl-L-lysyl-[protein] + NAD(+) = 2''-O-succinyl-ADP-D-ribose + L-lysyl-[protein] + nicotinamide H2O + N(6)-(2-hydroxyisobutanoyl)-L-lysyl-[protein] + NAD(+) = 2''-O-(2-hydroxyisobutanoyl)-ADP-D-ribose + L-lysyl-[protein] + nicotinamide Binds 1 zinc ion per subunit. kcat is 0.135 sec(-1) for acetyllysine peptide. kcat is 0.242 sec(-1) for succinyllysine peptide. Forms a 1:1 complex with acetyl-CoA synthetase (Acs). 2 residues (Tyr-92 and Arg-95) present in a large hydrophobic pocket are probably involved in substrate specificity. They are important for desuccinylation activity, but dispensable for deacetylation activity. Belongs to the sirtuin family. Class III subfamily. Was originally thought to be involved in cobalamin biosynthesis. In contrast to human SIRT5, which has only weak deacetylation activity, CobB shows comparable lysine deacetylation and lysine deacylation activities. PubMed:10381378 has reported that this protein has a weak ADP-ribosyltransferase activity, but that is probably not its primary activity in vivo. Truncated N-terminus.