Crystal structure of Maternal Embryonic Leucine Zipper Kinase (MELK)

Experimental Data Snapshot

  • Resolution: 2.75 Å
  • R-Value Free: 0.232 
  • R-Value Work: 0.202 
  • R-Value Observed: 0.203 

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Structural basis for the regulation of maternal embryonic leucine zipper kinase.

Cao, L.S.Wang, J.Chen, Y.Deng, H.Wang, Z.X.Wu, J.W.

(2013) PLoS One 8: e70031-e70031

  • DOI: https://doi.org/10.1371/journal.pone.0070031
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 

    MELK (maternal embryonic leucine zipper kinase), which is a member of the AMPK (AMP-activated protein kinase)-related kinase family, plays important roles in diverse cellular processes and has become a promising drug target for certain cancers. However, the regulatory mechanism of MELK remains elusive. Here, we report the crystal structure of a fragment of human MELK that contains the kinase domain and ubiquitin-associated (UBA) domain. The UBA domain tightly binds to the back of the kinase domain, which may contribute to the proper conformation and activity of the kinase domain. Interestingly, the activation segment in the kinase domain displays a unique conformation that contains an intramolecular disulfide bond. The structural and biochemical analyses unravel the molecular mechanisms for the autophosphorylation/activation of MELK and the dependence of its catalytic activity on reducing agents. Thus, our results may provide the basis for designing specific MELK inhibitors for cancer treatment.

  • Organizational Affiliation

    MOE Key Laboratory of Protein Sciences and Tsinghua-Peking Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing, China.

Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Maternal embryonic leucine zipper kinase348Homo sapiensMutation(s): 2 
Gene Names: MELKKIAA0175
EC: (PDB Primary Data), (PDB Primary Data)
UniProt & NIH Common Fund Data Resources
Find proteins for Q14680 (Homo sapiens)
Explore Q14680 
Go to UniProtKB:  Q14680
PHAROS:  Q14680
GTEx:  ENSG00000165304 
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupQ14680
Sequence Annotations
  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Resolution: 2.75 Å
  • R-Value Free: 0.232 
  • R-Value Work: 0.202 
  • R-Value Observed: 0.203 
  • Space Group: P 64 2 2
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 135.449α = 90
b = 135.449β = 90
c = 153.652γ = 120
Software Package:
Software NamePurpose
HKL-2000data collection
HKL-2000data reduction
HKL-2000data scaling

Structure Validation

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Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2013-09-11
    Type: Initial release
  • Version 1.1: 2023-09-20
    Changes: Data collection, Database references, Refinement description