Editing GSK-3 (section)

==Mechanism==
[[File:GSK3 active site.png|thumb|left|alt=Active site of GSK-3|The active site of GSK-3. The three residues in blue bind the priming phosphate on the substrate, as demonstrated by the ligand. Residues D181, D200, K85, and E97.]]

GSK-3 functions by [[phosphorylation|phosphorylating]] a serine or threonine residue on its target substrate. A positively charged pocket adjacent to the active site binds a "priming" phosphate group attached to a serine or threonine four residues C-terminal of the target phosphorylation site. The active site, at residues 181, 200, 97, and 85, binds the terminal phosphate of ATP and transfers it to the target location on the substrate (see figure 1).<ref name="pmid11440715">{{cite journal | vauthors = Dajani R, Fraser E, Roe SM, Young N, Good V, Dale TC, Pearl LH | title = Crystal structure of glycogen synthase kinase 3 beta: structural basis for phosphate-primed substrate specificity and autoinhibition | journal = Cell | volume = 105 | issue = 6 | pages = 721–732 | date = June 2001 | pmid = 11440715 | doi = 10.1016/S0092-8674(01)00374-9 | s2cid = 17401752 | doi-access = free }}</ref>