ATP-binding motif

[1] ATP is a molecule of energy, and can be a coenzyme, involved in a number of biological reactions.

[3] The genetic and functional similarity of such a motif demonstrates micro-evolution: proteins have co-opted the same binding sequence from other enzymes rather than developing them independently.

[6] The Walker site A has a primary amino acid sequence of GxxGxGKS or GxxGxGKT.

A mutation of any of these amino acids will affect the binding ATP or interfere with the catalytic activity of the enzyme.

[7] The primary amino acid sequence determines the three dimensional structure of each motif.

[3] All of the ATP binding domains are made up of an estimated 250 residues and two subunits, creating a dimer.

It is the histidine residue that forms the tight coupling between the binding of the ATP molecule and the dimer.

[6][9] Following the hydrolysis of ADP, a conformational change must occur to separate the ATP-binding cassette.