1V07

CRYSTAL STRUCTURE OF ThrE11Val mutant of THE NERVE TISSUE MINI-HEMOGLOBIN FROM THE NEMERTEAN WORM CEREBRATULUS LACTEUS


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.70 Å
  • R-Value Free: 0.195 
  • R-Value Work: 0.167 
  • R-Value Observed: 0.170 

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This is version 1.2 of the entry. See complete history


Literature

Thr-E11 Regulates O2 Affinity in Cerebratulus Lacteus Mini-Hemoglobin

Pesce, A.Nardini, M.Ascenzi, P.Geuens, E.Dewilde, S.Moens, L.Bolognesi, M.Riggs, A.Hale, A.Deng, P.Nienhaus, G.U.Olson, J.S.Nienhaus, K.

(2004) J Biol Chem 279: 33662

  • DOI: https://doi.org/10.1074/jbc.M403597200
  • Primary Citation of Related Structures:  
    1V07

  • PubMed Abstract: 

    The mini-hemoglobin from Cerebratulus lacteus (CerHb) belongs to a class of globins containing the polar Tyr-B10/Gln-E7 amino acid pair that normally causes low rates of O2 dissociation and ultra-high O2 affinity, which suggest O2 sensing or NO scavenging functions. CerHb, however, has high rates of O2 dissociation (kO2 = 200-600 s(-1)) and moderate O2 affinity (KO2) approximately 1 microm(-1)) as a result of a third polar amino acid in its active site, Thr-E11. When Thr-E11 is replaced by Val, kO2 decreases 1000-fold and KO2 increases 130-fold at pH 7.0, 20 degrees C. The mutation also shifts the stretching frequencies of both heme-bound and photodissociated CO, indicating marked changes of the electrostatic field at the active site. The crystal structure of Thr-E11 --> Val CerHbO2 at 1.70 A resolution is almost identical to that of the wild-type protein (root mean square deviation of 0.12 A). The dramatic functional and spectral effects of the Thr-E11 --> Val mutation are due exclusively to changes in the hydrogen bonding network in the active site. Replacing Thr-E11 with Val "frees" the Tyr-B10 hydroxyl group to rotate toward and donate a strong hydrogen bond to the heme-bound ligand, causing a selective increase in O2 affinity, a decrease of the rate coefficient for O2 dissociation, a 40 cm(-1) decrease in nuCO of heme-bound CO, and an increase in ligand migration toward more remote intermediate sites.


  • Organizational Affiliation

    Department of Physics-INFM and Center for Excellence in Biomedical Research, University of Genova, Via Dodecaneso 33, 16146 Genova, Italy.


Macromolecules
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Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
NEURAL HEMOGLOBIN110Cerebratulus lacteusMutation(s): 1 
UniProt
Find proteins for O76242 (Cerebratulus lacteus)
Explore O76242 
Go to UniProtKB:  O76242
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupO76242
Sequence Annotations
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.70 Å
  • R-Value Free: 0.195 
  • R-Value Work: 0.167 
  • R-Value Observed: 0.170 
  • Space Group: P 21 21 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 42.656α = 90
b = 43.422β = 90
c = 59.66γ = 90
Software Package:
Software NamePurpose
REFMACrefinement
DENZOdata reduction
SCALEPACKdata scaling

Structure Validation

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Entry History 

Revision History  (Full details and data files)

  • Version 1.0: 2004-06-03
    Type: Initial release
  • Version 1.1: 2011-05-07
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Version format compliance