InterPro domain: IPR013650

The ATP-grasp superfamily currently includes 17 groups of enzymes, catalysing ATP-dependent ligation of a carboxylate containing molecule to an amino or thiol group-containing molecule [ 1 ]. They contribute predominantly to macromolecular synthesis. ATP-hydrolysis is used to activate a substrate. For example, DD-ligase transfers phosphate from ATP to D-alanine on the first step of catalysis. On the second step the resulting acylphosphate is attacked by a second D-alanine to produce a DD dipeptide following phosphate elimination [ 2 ].

The ATP-grasp domain contains three conserved motifs, corresponding to the phosphate binding loop and the Mg(2+) binding site [ 3 ]. The fold is characterised by two alpha-beta subdomains that grasp the ATP molecule between them. Each subdomain provides a variable loop that forms a part of the active site, completed by region of other domains not conserved between the various ATP-grasp enzymes [ 4 ].

The ATP-grasp domain represented by this entry is found primarily in succinyl-CoA synthetases ( 6.2.1.5 ).

1. A diverse superfamily of enzymes with ATP-dependent carboxylate-amine/thiol ligase activity. Protein Sci. 6, 2639-43
2. Vancomycin resistance: structure of D-alanine:D-alanine ligase at 2.3 A resolution. Science 266, 439-43
3. Structural classification of proteins: new superfamilies. Curr. Opin. Struct. Biol. 6, 386-94
4. A common fold for peptide synthetases cleaving ATP to ADP: glutathione synthetase and D-alanine:d-alanine ligase of Escherichia coli. Proc. Natl. Acad. Sci. U.S.A. 92, 1172-6