Choline kinase
![Proposed choline binding site–The loops are colored as follows: the ATP binding loop (residues 81–88), red; residue Asp301, magenta; choline pocket loop 1 (residues 322–343), green;choline pocket loop 2 (residues 396–405), blue. On the right, the surface is colored on the basis of the electrostatic potential of the molecule.[6]](/Images/godic/202501/04/Proposed_Choline_Binding_Site4535.png")
Choline kinase (also known as CK,ChoK and choline phosphokinase) is an enzyme which catalyzes the first reaction in the choline pathway for phosphatidylcholine (PC) biosynthesis. This reaction involves the transfer of a phosphate group from adenosine triphosphate (ATP) to choline in order to form phosphocholine.