3MC2

Crystal Structure of the Murine Inhibitor of Carbonic Anhydrase


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.4 Å
  • R-Value Free: 0.301 
  • R-Value Work: 0.239 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

The structure and evolution of the murine inhibitor of carbonic anhydrase: A member of the transferrin superfamily.

Eckenroth, B.E.Mason, A.B.McDevitt, M.E.Lambert, L.A.Everse, S.J.

(2010) Protein Sci. 19: 1616-1626

  • DOI: 10.1002/pro.439

  • PubMed Abstract: 
  • The original signature of the transferrin (TF) family of proteins was the ability to bind ferric iron with high affinity in the cleft of each of two homologous lobes. However, in recent years, new family members that do not bind iron have been discov ...

    The original signature of the transferrin (TF) family of proteins was the ability to bind ferric iron with high affinity in the cleft of each of two homologous lobes. However, in recent years, new family members that do not bind iron have been discovered. One new member is the inhibitor of carbonic anhydrase (ICA), which as its name indicates, binds to and strongly inhibits certain isoforms of carbonic anhydrase. Recently, mouse ICA has been expressed as a recombinant protein in a mammalian cell system. Here, we describe the 2.4 Å structure of mouse ICA from a pseudomerohedral twinned crystal. As predicted, the structure is bilobal, comprised of two α-β domains per lobe typical of the other family members. As with all but insect TFs, the structure includes the unusual reverse γ-turn in each lobe. The structure is consistent with the fact that introduction of two mutations in the N-lobe of murine ICA (mICA) (W124R and S188Y) allowed it to bind iron with high affinity. Unexpectedly, both lobes of the mICA were found in the closed conformation usually associated with presence of iron in the cleft, and making the structure most similar to diferric pig TF. Two new ICA family members (guinea pig and horse) were identified from genomic sequences and used in evolutionary comparisons. Additionally, a comparison of selection pressure (dN/dS) on functional residues reveals some interesting insights into the evolution of the TF family including that the N-lobe of lactoferrin may be in the process of eliminating its iron binding function.


    Organizational Affiliation

    Department of Biochemistry, University of Vermont, Burlington, Vermont 05405, USA.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Inhibitor of Carbonic Anhydrase
A, B, C, D
687Mus musculusMutation(s): 2 
Gene Names: Ica
Find proteins for Q9DBD0 (Mus musculus)
Go to UniProtKB:  Q9DBD0
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.4 Å
  • R-Value Free: 0.301 
  • R-Value Work: 0.239 
  • Space Group: P 1 21 1
Unit Cell:
Length (Å)Angle (°)
a = 68.559α = 90.00
b = 136.928β = 90.11
c = 155.575γ = 90.00
Software Package:
Software NamePurpose
REFMACrefinement
SCALEPACKdata scaling
PDB_EXTRACTdata extraction
HKL-2000data scaling
DENZOdata reduction
MAR345dtbdata collection
HKL-2000data reduction
PHASERphasing
CNSrefinement

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2010-07-28
    Type: Initial release
  • Version 1.1: 2011-07-13
    Type: Version format compliance
  • Version 1.2: 2017-11-08
    Type: Advisory, Refinement description