Abstract
The MST family is a subclass of mammalian serine/threonine kinases that are related to the yeast sterile-20 protein and are implicated in regulating cell growth and transformation. The MST3 protein contains a 300-residue catalytic domain and a 130-residue regulatory domain, which can be cleaved by caspase and activated by autophosphorylation, promoting apoptosis. Here, five crystal structures of the catalytic domain of MST3 are presented, including a complex with ADP and manganese, a unique cofactor preferred by the enzyme, and a complex with adenine. Similar to other protein kinases, the catalytic domain of MST3 folds into two lobes: the smaller N lobe forms the nucleotide-binding site and the larger C lobe recognizes the polypeptide substrate. The bound ADP and Mn2+ ions are covered by a glycine-rich loop and held in place by Asn149 and Asp162. A different orientation was observed for the ligand in the MST3-adenine complex. In the activation loop, the side chain of Thr178 is phosphorylated and is sandwiched by Arg143 and Arg176. Comparison of this structure with other similar kinase structures shows a 180° rotation of the loop, leading to activation of the enzyme. The well defined protein-ligand interactions also provide useful information for the design of potent inhibitors.
Original language | English |
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Pages (from-to) | 145-154 |
Number of pages | 10 |
Journal | Acta Crystallographica Section D: Biological Crystallography |
Volume | 66 |
Issue number | 2 |
DOIs | |
Publication status | Published - 2010 |
Externally published | Yes |
ASJC Scopus subject areas
- Structural Biology