3E2W

H. influenzae beta-carbonic anhydrase, variant Y181F with 1M bicarbonate


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.296 Å
  • R-Value Free: 0.242 
  • R-Value Work: 0.205 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Allosteric site variants of Haemophilus influenzae beta-carbonic anhydrase.

Rowlett, R.S.Tu, C.Lee, J.Herman, A.G.Chapnick, D.A.Shah, S.H.Gareiss, P.C.

(2009) Biochemistry 48: 6146-6156

  • DOI: 10.1021/bi900663h
  • Primary Citation of Related Structures:  3E1V, 3E1W, 3E24, 3E28, 3E2A

  • PubMed Abstract: 
  • Haemophilus influenzae beta-carbonic anhydrase (HICA) is hypothesized to be an allosteric protein that is regulated by the binding of bicarbonate ion to a non-catalytic (inhibitory) site that controls the ligation of Asp44 to the catalytically essent ...

    Haemophilus influenzae beta-carbonic anhydrase (HICA) is hypothesized to be an allosteric protein that is regulated by the binding of bicarbonate ion to a non-catalytic (inhibitory) site that controls the ligation of Asp44 to the catalytically essential zinc ion. We report here the X-ray crystallographic structures of two variants (W39F and Y181F) involved in the binding of bicarbonate ion in the non-catalytic site and an active-site variant (D44N) that is incapable of forming a strong zinc ligand. The alteration of Trp39 to Phe increases the apparent K(i) for bicarbonate inhibition by 4.8-fold. While the structures of W39F and Y181F are very similar to the wild-type enzyme, the X-ray crystal structure of the D44N variant reveals that it has adopted an active-site conformation nearly identical to that of non-allosteric beta-carbonic anhydrases. We propose that the structure of the D44N variant is likely to be representative of the active conformation of the enzyme. These results lend additional support to the hypothesis that HICA is an allosteric enzyme that can adopt active and inactive conformations, the latter of which is stabilized by bicarbonate ion binding to a non-catalytic site.


    Organizational Affiliation

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




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Carbonic anhydrase 2
A, B, C, D, E, F
229Haemophilus influenzae (strain ATCC 51907 / DSM 11121 / KW20 / Rd)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 3 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
ZN
Query on ZN

Download SDF File 
Download CCD File 
A, B, C, D, E, F
ZINC ION
Zn
PTFCDOFLOPIGGS-UHFFFAOYSA-N
 Ligand Interaction
SO4
Query on SO4

Download SDF File 
Download CCD File 
A, B, C, D, E, F
SULFATE ION
O4 S
QAOWNCQODCNURD-UHFFFAOYSA-L
 Ligand Interaction
BCT
Query on BCT

Download SDF File 
Download CCD File 
F
BICARBONATE ION
C H O3
BVKZGUZCCUSVTD-UHFFFAOYSA-M
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.296 Å
  • R-Value Free: 0.242 
  • R-Value Work: 0.205 
  • Space Group: C 1 2 1
Unit Cell:
Length (Å)Angle (°)
a = 250.141α = 90.00
b = 145.225β = 93.78
c = 53.499γ = 90.00
Software Package:
Software NamePurpose
DENZOdata reduction
EPMRphasing
SCALEPACKdata scaling
REFMACrefinement

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

  • Deposited Date: 2008-08-06 
  • 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, Refinement description, Version format compliance
  • Version 1.2: 2017-10-25
    Type: Refinement description