Crystal structure of the 14-3-3zeta:serotonin N-acetyltransferase complex. a role for scaffolding in enzyme regulation.
Serotonin N-acetyltransferase (AANAT) controls the daily rhythm in melatonin synthesis. When isolated from tissue, AANAT copurifies with isoforms epsilon and zeta of 14-3-3. We have determined the structure of AANAT bound to 14-3-3zeta, an association that is phosphorylation dependent. AANAT is bound in the central channel of the 14-3-3zeta dimer, and is held in place by extensive interactions both with the amphipathic phosphopeptide binding groove of 14-3-3zeta and with other parts of the central channel. Thermodynamic and activity measurements, together with crystallographic analysis, indicate that binding of AANAT by 14-3-3zeta modulates AANAT's activity and affinity for its substrates by stabilizing a region of AANAT involved in substrate binding.
Pubmed ID: 11336675 RIS Download
14-3-3 Proteins | Animals | Arylamine N-Acetyltransferase | Calorimetry | Crystallography, X-Ray | Genes, Reporter | Humans | Models, Molecular | Protein Binding | Protein Structure, Quaternary | Protein Structure, Tertiary | Recombinant Fusion Proteins | Sheep | Tyrosine 3-Monooxygenase