3E31

H. influenzae beta-carbonic anhydrase, variant V47A


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.95 Å
  • R-Value Free: 0.247 
  • R-Value Work: 0.197 

wwPDB Validation 3D Report Full Report


This is version 1.1 of the entry. See complete history

Literature

Evidence for a bicarbonate "escort" site in Haemophilus influenzae beta-carbonic anhydrase .

Rowlett, R.S.Hoffmann, K.M.Failing, H.Mysliwiec, M.M.Samardzic, D.

(2010) Biochemistry 49: 3640-3647

  • DOI: 10.1021/bi100328j
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 
  • The Haemophilus influenzae beta-carbonic anhydrase (HICA) allosteric site variants V47A and G41A were overexpressed and purified to homogeneity. These variants have k(cat)/K(m) values similar to that of the wild-type enzyme and exhibit a similar dram ...

    The Haemophilus influenzae beta-carbonic anhydrase (HICA) allosteric site variants V47A and G41A were overexpressed and purified to homogeneity. These variants have k(cat)/K(m) values similar to that of the wild-type enzyme and exhibit a similar dramatic decrease in catalytic activity at pH <8.0. However, both HICA-G41A and -V47A were serendipitously found to bind sulfate ion or bicarbonate ion near pairs of Glu50 and Arg64 residues located on the dimerization interface. In the case of HICA-V47A, bicarbonate ions simultaneously bind to both the dimerization interface and the allosteric sites. For HICA-G41A, two of 12 chains in the asymmetric unit bind bicarbonate ion exclusively at the dimerization interface, while the remaining 10 chains bind bicarbonate ion exclusively at the allosteric site. We propose that the new anion binding site along the dimerization interface of HICA is an "escort" site that represents an intermediate along the ingress and egress route of bicarbonate ion to and from the allosteric binding site, respectively. The structural evidence for sulfate binding at the escort site suggests that the mechanism of sulfate activation of HICA is the result of sulfate ion competing for bicarbonate at the escort site, preventing passage of bicarbonate from the bulk solution to its allosteric site.


    Organizational Affiliation

    Department of Chemistry, Colgate University, 13 Oak Drive, Hamilton, New York 13346, USA. rrowlett@colgate.edu




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Carbonic anhydrase 2
A, B
229Haemophilus influenzae (strain ATCC 51907 / DSM 11121 / KW20 / Rd)Mutation(s): 1 
Gene Names: can
EC: 4.2.1.1
Find proteins for P45148 (Haemophilus influenzae (strain ATCC 51907 / DSM 11121 / KW20 / Rd))
Go to UniProtKB:  P45148
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
ZN
Query on ZN

Download SDF File 
Download CCD File 
A, B
ZINC ION
Zn
PTFCDOFLOPIGGS-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.95 Å
  • R-Value Free: 0.247 
  • R-Value Work: 0.197 
  • Space Group: P 41 21 2
Unit Cell:
Length (Å)Angle (°)
a = 82.277α = 90.00
b = 82.277β = 90.00
c = 188.783γ = 90.00
Software Package:
Software NamePurpose
PHASERphasing
REFMACrefinement
MOSFLMdata reduction
PDB_EXTRACTdata extraction
SCALAdata scaling

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

  • Deposited Date: 2008-08-05 
  • Released Date: 2009-08-18 
  • Deposition Author(s): Rowlett, R.S., Lee, J.

Revision History 

  • Version 1.0: 2009-08-18
    Type: Initial release
  • Version 1.1: 2011-07-13
    Type: Advisory, Version format compliance