6IH1

Crystal structure of a standalone versatile EAL protein from Vibrio cholerae O395 - c-di-GMP bound form


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.95 Å
  • R-Value Free: 0.222 
  • R-Value Work: 0.183 
  • R-Value Observed: 0.185 

wwPDB Validation 3D Report Full Report


This is version 1.1 of the entry. See complete history


Literature

Structures of c-di-GMP/cGAMP degrading phosphodiesterase VcEAL: identification of a novel conformational switch and its implication.

Yadav, M.Pal, K.Sen, U.

(2019) Biochem J 476: 3333-3353

  • DOI: 10.1042/BCJ20190399
  • Primary Citation of Related Structures:  
    6IFQ, 6IH1, 6IH7, 6IJ2

  • PubMed Abstract: 
  • Cyclic dinucleotides (CDNs) have emerged as the central molecules that aid bacteria to adapt and thrive in changing environmental conditions. Therefore, tight regulation of intracellular CDN concentration by counteracting the action of dinucleotide c ...

    Cyclic dinucleotides (CDNs) have emerged as the central molecules that aid bacteria to adapt and thrive in changing environmental conditions. Therefore, tight regulation of intracellular CDN concentration by counteracting the action of dinucleotide cyclases and phosphodiesterases (PDEs) is critical. Here, we demonstrate that a putative stand-alone EAL domain PDE from Vibrio cholerae (VcEAL) is capable to degrade both the second messenger c-di-GMP and hybrid 3'3'-cyclic GMP-AMP (cGAMP). To unveil their degradation mechanism, we have determined high-resolution crystal structures of VcEAL with Ca2+, c-di-GMP-Ca2+, 5'-pGpG-Ca2+ and cGAMP-Ca2+, the latter provides the first structural basis of cGAMP hydrolysis. Structural studies reveal a typical triosephosphate isomerase barrel-fold with substrate c-di-GMP/cGAMP bound in an extended conformation. Highly conserved residues specifically bind the guanine base of c-di-GMP/cGAMP in the G2 site while the semi-conserved nature of residues at the G1 site could act as a specificity determinant. Two metal ions, co-ordinated with six stubbornly conserved residues and two non-bridging scissile phosphate oxygens of c-di-GMP/cGAMP, activate a water molecule for an in-line attack on the phosphodiester bond, supporting two-metal ion-based catalytic mechanism. PDE activity and biofilm assays of several prudently designed mutants collectively demonstrate that VcEAL active site is charge and size optimized. Intriguingly, in VcEAL-5'-pGpG-Ca2+ structure, β5-α5 loop adopts a novel conformation that along with conserved E131 creates a new metal-binding site. This novel conformation along with several subtle changes in the active site designate VcEAL-5'-pGpG-Ca2+ structure quite different from other 5'-pGpG bound structures reported earlier.


    Organizational Affiliation

    Crystallography and Molecular Biology Division, Saha Institute of Nuclear Physics, HBNI, 1/AF Bidhan Nagar, Kolkata 700064, India.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
cyclic di nucleotide phoshodiesteraseABCD257Vibrio cholerae O395Mutation(s): 0 
Gene Names: VC0395_A1247
EC: 3.1.4.52
Find proteins for A0A0H3AJ04 (Vibrio cholerae serotype O1 (strain ATCC 39541 / Classical Ogawa 395 / O395))
Explore A0A0H3AJ04 
Go to UniProtKB:  A0A0H3AJ04
Protein Feature View
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  • Reference Sequence
Small Molecules
Ligands 2 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
C2E
Query on C2E

Download CCD File 
A, B, C, D
9,9'-[(2R,3R,3aS,5S,7aR,9R,10R,10aS,12S,14aR)-3,5,10,12-tetrahydroxy-5,12-dioxidooctahydro-2H,7H-difuro[3,2-d:3',2'-j][1,3,7,9,2,8]tetraoxadiphosphacyclododecine-2,9-diyl]bis(2-amino-1,9-dihydro-6H-purin-6-one)
C20 H24 N10 O14 P2
PKFDLKSEZWEFGL-MHARETSRSA-N
 Ligand Interaction
CA
Query on CA

Download CCD File 
A, B, C, D
CALCIUM ION
Ca
BHPQYMZQTOCNFJ-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.95 Å
  • R-Value Free: 0.222 
  • R-Value Work: 0.183 
  • R-Value Observed: 0.185 
  • Space Group: P 1 21 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 73.5α = 90
b = 42.63β = 94.42
c = 156.34γ = 90
Software Package:
Software NamePurpose
PHENIXrefinement
Aimlessdata scaling
PDB_EXTRACTdata extraction
MOSFLMdata reduction
PHASERphasing

Structure Validation

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Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2019-10-02
    Type: Initial release
  • Version 1.1: 2020-01-22
    Changes: Database references, Structure summary