3TPM

Crystal structure of MAL RPEL domain in complex with importin-alpha


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.1 Å
  • R-Value Free: 0.208 
  • R-Value Work: 0.166 

wwPDB Validation 3D Report Full Report


This is version 1.1 of the entry. See complete history

Literature

Sensing actin dynamics: structural basis for G-actin-sensitive nuclear import of MAL

Hirano, H.Matsuura, Y.

(2011) Biochem.Biophys.Res.Commun. 414: 373-378

  • DOI: 10.1016/j.bbrc.2011.09.079
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 
  • The coordination of cytoskeletal actin dynamics with gene expression reprogramming is emerging as a crucial mechanism to control diverse cellular processes, including cell migration, differentiation and neuronal circuit assembly. The actin-binding tr ...

    The coordination of cytoskeletal actin dynamics with gene expression reprogramming is emerging as a crucial mechanism to control diverse cellular processes, including cell migration, differentiation and neuronal circuit assembly. The actin-binding transcriptional coactivator MAL (also known as MRTF-A/MKL1/BSAC) senses G-actin concentration and transduces Rho GTPase signals to serum response factor (SRF). MAL rapidly shuttles between the cytoplasm and the nucleus in unstimulated cells but Rho-induced depletion of G-actin leads to MAL nuclear accumulation and activation of transcription of SRF:MAL-target genes. Although the molecular and structural basis of actin-regulated nucleocytoplasmic shuttling of MAL is not understood fully, it is proposed that nuclear import of MAL is mediated by importin α/β heterodimer, and that G-actin competes with importin α/β for the binding to MAL. Here we present structural, biochemical and cell biological evidence that MAL has a classical bipartite nuclear localization signal (NLS) in the N-terminal 'RPEL' domain containing Arg-Pro-X-X-X-Glu-Leu (RPEL) motifs. The NLS residues of MAL adopt an extended conformation and bind along the surface groove of importin-α, interacting with the major- and minor-NLS binding sites. We also present a crystal structure of wild-type MAL RPEL domain in complex with five G-actins. Comparison of the importin-α- and actin-complexes revealed that the binding of G-actins to MAL is associated with folding of NLS residues into a helical conformation that is inappropriate for importin-α recognition.


    Organizational Affiliation

    Structural Biology Research Center, Graduate School of Science, Nagoya University, Nagoya 464-8602, Japan.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Importin subunit alpha-2
A
422Mus musculusMutation(s): 0 
Gene Names: Kpna2 (Rch1)
Find proteins for P52293 (Mus musculus)
Go to UniProtKB:  P52293
Entity ID: 2
MoleculeChainsSequence LengthOrganismDetails
MAL
B
120N/AMutation(s): 0 
Protein Feature View is not available: No corresponding UniProt sequence found.
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.1 Å
  • R-Value Free: 0.208 
  • R-Value Work: 0.166 
  • Space Group: P 21 21 21
Unit Cell:
Length (Å)Angle (°)
a = 78.658α = 90.00
b = 90.116β = 90.00
c = 98.853γ = 90.00
Software Package:
Software NamePurpose
PDB_EXTRACTdata extraction
SCALAdata scaling
REFMACrefinement
MOSFLMdata reduction

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2011-10-12
    Type: Initial release
  • Version 1.1: 2013-06-26
    Type: Database references