PDBsum entry 4bfm

Transferase

PDB id: 4bfm

Contents

Protein chain

313 a.a.

Ligands

ANP

SO4 ×6

Waters ×82

References listed in PDB file

Key reference

• Title: The structures of the kinase domain and uba domain of mpk38 suggest the activation mechanism for kinase activity.
• Authors: Y.S.Cho, J.Yoo, S.Park, H.S.Cho.
• Ref.: Acta Crystallogr D Biol Crystallogr, 2014, 70, 514-521. [DOI no: 10.1107/S1399004713027806]
• PubMed id: 24531485

Abstract

Murine protein serine/threonine kinase 38 (MPK38) is the murine orthologue of human maternal embryonic leucine-zipper kinase (MELK), which belongs to the SNF1/AMPK family. MELK is considered to be a promising drug target for anticancer therapy because overexpression and hyperactivation of MELK is correlated with several human cancers. Activation of MPK38 requires the extended sequence (ExS) containing the ubiquitin-associated (UBA) linker and UBA domain and phosphorylation of the activation loop. However, the activation mechanism of MPK38 is unknown. This paper reports the crystal structure of MPK38 (T167E), which mimics a phosphorylated state of the activation loop, in complex with AMP-PNP. In the MPK38 structure, the UBA linker forces an inward movement of the αC helix. Phosphorylation of the activation loop then induces movement of the activation loop towards the C-lobe and results in interlobar cleft closure. These processes generate a fully active state of MPK38. This structure suggests that MPK38 has a similar molecular mechanism regulating activation as in other kinases of the SNF1/AMPK family.