In molecular biology, the ATP-grasp fold is a unique ATP-binding protein structural motif made of two ñ+ò subdomains that "grasp" a molecule of ATP between them. ATP-grasp proteins have ATP-dependent carboxylate-amine/thiol ligase activity.
Proteins of the ATP-grasp family have an overall structural configuration organised into three domains referred to as the N-terminal domain (or A-domain), the central domain (or B-domain), and the C-terminal domain (or C-domain).
ATP-grasp enzymes catalyse the ATP-dependent ligation of a carboxylate-containing molecule to an amino or thiol group-containing molecule. The reactions typically involve formation of acylphosphate intermediates. These enzymes are involved in various metabolic pathways including purine biosynthesis, fatty acid synthesis, and gluconeogenesis.
The ATP-grasp fold is evolutionarily conserved across different enzyme families and its presence is ubiquitous across prokaryotes and eukaryotes.
Researchers have developed several types of inhibitors for these enzymes, including mechanism-based inhibitors, ATP-competitive inhibitors, and non-competitive inhibitors. Some ATP-grasp enzymes are being studied as potential targets for antibiotics and anti-obesity drugs.