6JQC

The structural basis of the beta-carbonic anhydrase CafC (wild type) of the filamentous fungus Aspergillus fumigatus


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.80 Å
  • R-Value Free: 0.249 
  • R-Value Work: 0.198 
  • R-Value Observed: 0.200 

wwPDB Validation 3D Report Full Report


This is version 1.1 of the entry. See complete history


Literature

The structural basis of the low catalytic activities of the two minor beta-carbonic anhydrases of the filamentous fungus Aspergillus fumigatus.

Kim, S.Kim, N.J.Hong, S.Kim, S.Sung, J.Jin, M.S.

(2019) J Struct Biol 208: 61-68

  • DOI: 10.1016/j.jsb.2019.07.011
  • Primary Citation of Related Structures:  
    6JQE, 6JQD, 6JQC

  • PubMed Abstract: 
  • The β-carbonic anhydrases (β-CAs) are widely distributed zinc-metalloenzymes that play essential roles in growth, survival, development and virulence in fungi. The majority of filamentous ascomycetes possess multiple β-CA isoforms among which major a ...

    The β-carbonic anhydrases (β-CAs) are widely distributed zinc-metalloenzymes that play essential roles in growth, survival, development and virulence in fungi. The majority of filamentous ascomycetes possess multiple β-CA isoforms among which major and minor forms have been characterized. We examined the catalytic behavior of the two minor β-CAs, CafC and CafD, of Aspergillus fumigatus, and found that both enzymes exhibited low CO 2 hydration activities. To understand the structural basis of their low activities, we performed X-ray crystallographic and site-directed mutagenesis studies. Both enzymes exist as homodimers. Like other Type-I β-CAs, the CafC active site has an "open" conformation in which the zinc ion is tetrahedrally coordinated by three residues (C36, H88 and C91) and a water molecule. However, L25 and L78 on the rim of the catalytic entry site protrude into the active site cleft, partially occluding access to it. Single (L25G or L78G) and double mutants provided evidence that widening the entrance to the active site greatly accelerates catalytic activity. By contrast, CafD has a typical Type-II "closed" conformation in which the zinc-bound water molecule is replaced by aspartic acid (D36). The most likely explanation for this result is that an arginine that is largely conserved within the β-CA family is replaced by glycine (G38), so that D36 cannot undergo a conformational change by forming a D-R pair that creates the space for a zinc-bound water molecule and switches the enzyme to the active form. The CafD structure also reveals the presence of a "non-catalytic" zinc ion in the dimer interface, which may contribute to stabilizing the dimeric assembly.


    Organizational Affiliation

    School of Life Sciences, GIST, 123 Cheomdan-gwagiro, Buk-gu, Gwangju 61005, Republic of Korea. Electronic address: misunjin@gist.ac.kr.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
Carbonic anhydraseA, B164Aspergillus fumigatus Af293Mutation(s): 0 
Gene Names: AFUA_4G09420
EC: 4.2.1.1
Find proteins for Q4WPJ0 (Neosartorya fumigata (strain ATCC MYA-4609 / Af293 / CBS 101355 / FGSC A1100))
Explore Q4WPJ0 
Go to UniProtKB:  Q4WPJ0
Protein Feature View
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  • Reference Sequence
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
ZN
Query on ZN

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

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.80 Å
  • R-Value Free: 0.249 
  • R-Value Work: 0.198 
  • R-Value Observed: 0.200 
  • Space Group: P 1 21 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 42.575α = 90
b = 80.066β = 115.84
c = 48.791γ = 90
Software Package:
Software NamePurpose
REFMACrefinement
HKL-2000data reduction
HKL-2000data scaling
PHASERphasing

Structure Validation

View Full Validation Report



Entry History & Funding Information

Deposition Data


Funding OrganizationLocationGrant Number
National Research Foundation (Korea)Korea, Republic OfNRF-2017R1A2B4003278
National Research Foundation (Korea)Korea, Republic OfNRF-2017M3A9F6029753

Revision History 

  • Version 1.0: 2019-08-14
    Type: Initial release
  • Version 1.1: 2019-10-02
    Changes: Data collection, Database references