3ZJP

M.acetivorans protoglobin in complex with imidazole


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.38 Å
  • R-Value Free: 0.198 
  • R-Value Work: 0.159 
  • R-Value Observed: 0.161 

wwPDB Validation 3D Report Full Report


This is version 1.1 of the entry. See complete history


Literature

Structure and Haem-Distal Site Plasticity in Methanosarcina Acetivorans Protoglobin.

Pesce, A.Tilleman, L.Donne, J.Aste, E.Ascenzi, P.Ciaccio, C.Coletta, M.Moens, L.Viappiani, C.Dewilde, S.Bolognesi, M.Nardini, M.

(2013) PLoS One 8: 66144

  • DOI: 10.1371/journal.pone.0066144
  • Structures With Same Primary Citation

  • PubMed Abstract: 
  • Protoglobin from Methanosarcina acetivorans C2A (MaPgb), a strictly anaerobic methanogenic Archaea, is a dimeric haem-protein whose biological role is still unknown. As other globins, protoglobin can bind O2, CO and NO reversibly in vitro, but it dis ...

    Protoglobin from Methanosarcina acetivorans C2A (MaPgb), a strictly anaerobic methanogenic Archaea, is a dimeric haem-protein whose biological role is still unknown. As other globins, protoglobin can bind O2, CO and NO reversibly in vitro, but it displays specific functional and structural properties within members of the hemoglobin superfamily. CO binding to and dissociation from the haem occurs through biphasic kinetics, which arise from binding to (and dissociation from) two distinct tertiary states in a ligation-dependent equilibrium. From the structural viewpoint, protoglobin-specific loops and a N-terminal extension of 20 residues completely bury the haem within the protein matrix. Thus, access of small ligand molecules to the haem is granted by two apolar tunnels, not common to other globins, which reach the haem distal site from locations at the B/G and B/E helix interfaces. Here, the roles played by residues Trp(60)B9, Tyr(61)B10 and Phe(93)E11 in ligand recognition and stabilization are analyzed, through crystallographic investigations on the ferric protein and on selected mutants. Specifically, protein structures are reported for protoglobin complexes with cyanide, with azide (also in the presence of Xenon), and with more bulky ligands, such as imidazole and nicotinamide. Values of the rate constant for cyanide dissociation from ferric MaPgb-cyanide complexes have been correlated to hydrogen bonds provided by Trp(60)B9 and Tyr(61)B10 that stabilize the haem-Fe(III)-bound cyanide. We show that protoglobin can strikingly reshape, in a ligand-dependent way, the haem distal site, where Phe(93)E11 acts as ligand sensor and controls accessibility to the haem through the tunnel system by modifying the conformation of Trp(60)B9.


    Organizational Affiliation

    Department of Physics, University of Genova, Genova, Italy.



Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
PROTOGLOBINA195Methanosarcina acetivoransMutation(s): 1 
Find proteins for Q8TLY9 (Methanosarcina acetivorans (strain ATCC 35395 / DSM 2834 / JCM 12185 / C2A))
Explore Q8TLY9 
Go to UniProtKB:  Q8TLY9
Protein Feature View
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  • Reference Sequence
Small Molecules
Ligands 4 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
HEM
Query on HEM

Download CCD File 
A
PROTOPORPHYRIN IX CONTAINING FE
C34 H32 Fe N4 O4
KABFMIBPWCXCRK-RGGAHWMASA-L
 Ligand Interaction
PO4
Query on PO4

Download CCD File 
A
PHOSPHATE ION
O4 P
NBIIXXVUZAFLBC-UHFFFAOYSA-K
 Ligand Interaction
GOL
Query on GOL

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A
GLYCEROL
C3 H8 O3
PEDCQBHIVMGVHV-UHFFFAOYSA-N
 Ligand Interaction
IMD
Query on IMD

Download CCD File 
A
IMIDAZOLE
C3 H5 N2
RAXXELZNTBOGNW-UHFFFAOYSA-O
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.38 Å
  • R-Value Free: 0.198 
  • R-Value Work: 0.159 
  • R-Value Observed: 0.161 
  • Space Group: C 1 2 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 79.97α = 90
b = 49.06β = 92.48
c = 51.43γ = 90
Software Package:
Software NamePurpose
REFMACrefinement
MOSFLMdata reduction
SCALAdata scaling
PHASERphasing

Structure Validation

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Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2013-06-26
    Type: Initial release
  • Version 1.1: 2016-12-21
    Changes: Database references, Structure summary