6I2Q

Crystal structure of the wild-type SucA domain of Mycobacterium smegmatis KGD (alpha-ketoglutarate decarboxylase), in complex with GarA


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.15 Å
  • R-Value Free: 0.191 
  • R-Value Work: 0.163 
  • R-Value Observed: 0.165 

wwPDB Validation   3D Report Full Report


Ligand Structure Quality Assessment 


This is version 1.1 of the entry. See complete history

Re-refinement Note

This entry reflects an alternative modeling of the original data in: 2XT9


Literature

Structural insights into the functional versatility of an FHA domain protein in mycobacterial signaling.

Wagner, T.Andre-Leroux, G.Hindie, V.Barilone, N.Lisa, M.N.Hoos, S.Raynal, B.Vulliez-Le Normand, B.O'Hare, H.M.Bellinzoni, M.Alzari, P.M.

(2019) Sci Signal 12

  • DOI: https://doi.org/10.1126/scisignal.aav9504
  • Primary Citation of Related Structures:  
    6I2P, 6I2Q, 6I2R, 6I2S

  • PubMed Abstract: 

    Forkhead-associated (FHA) domains are modules that bind to phosphothreonine (pThr) residues in signaling cascades. The FHA-containing mycobacterial protein GarA is a central element of a phosphorylation-dependent signaling pathway that redirects metabolic flux in response to amino acid starvation or cell growth requirements. GarA acts as a phosphorylation-dependent ON/OFF molecular switch. In its nonphosphorylated ON state, the GarA FHA domain engages in phosphorylation-independent interactions with various metabolic enzymes that orchestrate nitrogen flow, such as 2-oxoglutarate decarboxylase (KGD). However, phosphorylation at the GarA N-terminal region by the protein kinase PknB or PknG triggers autoinhibition through the intramolecular association of the N-terminal domain with the FHA domain, thus blocking all downstream interactions. To investigate these different FHA binding modes, we solved the crystal structures of the mycobacterial upstream (phosphorylation-dependent) complex PknB-GarA and the downstream (phosphorylation-independent) complex GarA-KGD. Our results show that the phosphorylated activation loop of PknB serves as a docking site to recruit GarA through canonical FHA-pThr interactions. However, the same GarA FHA-binding pocket targets an allosteric site on nonphosphorylated KGD, where a key element of recognition is a phosphomimetic aspartate. Further enzymatic and mutagenesis studies revealed that GarA acted as a dynamic allosteric inhibitor of KGD by preventing crucial motions in KGD that are necessary for catalysis. Our results provide evidence for physiological phosphomimetics, supporting numerous mutagenesis studies using such approaches, and illustrate how evolution can shape a single FHA-binding pocket to specifically interact with multiple phosphorylated and nonphosphorylated protein partners.


  • Organizational Affiliation

    Leicester Tuberculosis Research Group (LTBRG) and Leicester Institute of Structural and Chemical Biology (LISCB), Department of Respiratory Science & Department of Molecular and Cell Biology, University of Leicester, Leicester LE1 7RH, UK.


Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Multifunctional 2-oxoglutarate metabolism enzyme868Mycolicibacterium smegmatis MC2 155Mutation(s): 0 
Gene Names: kgdsucAMSMEG_5049MSMEI_4922
EC: 2.2.1.5 (PDB Primary Data), 4.1.1.71 (PDB Primary Data), 1.2.4.2 (PDB Primary Data), 2.3.1.61 (PDB Primary Data)
UniProt
Find proteins for A0R2B1 (Mycolicibacterium smegmatis (strain ATCC 700084 / mc(2)155))
Explore A0R2B1 
Go to UniProtKB:  A0R2B1
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupA0R2B1
Sequence Annotations
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  • Reference Sequence
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 2
MoleculeChains Sequence LengthOrganismDetailsImage
Glycogen accumulation regulator GarA115Mycolicibacterium smegmatis MC2 155Mutation(s): 0 
Gene Names: garAMSMEG_3647MSMEI_3561
UniProt
Find proteins for A0QYG2 (Mycolicibacterium smegmatis (strain ATCC 700084 / mc(2)155))
Explore A0QYG2 
Go to UniProtKB:  A0QYG2
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupA0QYG2
Sequence Annotations
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.15 Å
  • R-Value Free: 0.191 
  • R-Value Work: 0.163 
  • R-Value Observed: 0.165 
  • Space Group: C 2 2 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 141.25α = 90
b = 167.846β = 90
c = 102.808γ = 90
Software Package:
Software NamePurpose
BUSTERrefinement
XDSdata reduction
Aimlessdata scaling
MOLREPphasing

Structure Validation

View Full Validation Report



Ligand Structure Quality Assessment 


Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2019-05-22
    Type: Initial release
  • Version 1.1: 2024-01-24
    Changes: Data collection, Database references, Refinement description