PDBsum entry 3e1v

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protein metals Protein-protein interface(s) links
Lyase PDB id
Protein chains
182 a.a. *
_ZN ×2
Waters ×21
* Residue conservation analysis
PDB id:
Name: Lyase
Title: H. Influenzae beta-carbonic anhydrase, variant d44n
Structure: Carbonic anhydrase 2. Chain: a, b. Synonym: carbonate dehydratase 2. Engineered: yes. Mutation: yes
Source: Haemophilus influenzae. Organism_taxid: 727. Gene: can, hi1301. Expressed in: escherichia coli. Expression_system_taxid: 562.
2.80Å     R-factor:   0.196     R-free:   0.233
Authors: R.S.Rowlett,D.A.Chapnick,S.Shah
Key ref: R.S.Rowlett et al. (2009). Allosteric site variants of Haemophilus influenzae beta-carbonic anhydrase. Biochemistry, 48, 6146-6156. PubMed id: 19459702
04-Aug-08     Release date:   02-Jun-09    
Go to PROCHECK summary

Protein chains
Pfam   ArchSchema ?
P45148  (CAN_HAEIN) -  Carbonic anhydrase 2
229 a.a.
182 a.a.*
Key:    PfamA domain  Secondary structure  CATH domain
* PDB and UniProt seqs differ at 1 residue position (black cross)

 Enzyme reactions 
   Enzyme class: E.C.  - Carbonate dehydratase.
[IntEnz]   [ExPASy]   [KEGG]   [BRENDA]
      Reaction: H2CO3 = CO2 + H2O
= CO(2)
+ H(2)O
      Cofactor: Zn(2+)
Molecule diagrams generated from .mol files obtained from the KEGG ftp site
 Gene Ontology (GO) functional annotation 
  GO annot!
  Cellular component     cellular_component   1 term 
  Biological process     metabolic process   2 terms 
  Biochemical function     lyase activity     4 terms  


    Added reference    
Biochemistry 48:6146-6156 (2009)
PubMed id: 19459702  
Allosteric site variants of Haemophilus influenzae beta-carbonic anhydrase.
R.S.Rowlett, C.Tu, J.Lee, A.G.Herman, D.A.Chapnick, S.H.Shah, P.C.Gareiss.
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.

Literature references that cite this PDB file's key reference

  PubMed id Reference
20659325 L.Syrjänen, M.Tolvanen, M.Hilvo, A.Olatubosun, A.Innocenti, A.Scozzafava, J.Leppiniemi, B.Niederhauser, V.P.Hytönen, T.A.Gorr, S.Parkkila, and C.T.Supuran (2010).
Characterization of the first beta-class carbonic anhydrase from an arthropod (Drosophila melanogaster) and phylogenetic analysis of beta-class carbonic anhydrases in invertebrates.
  BMC Biochem, 11, 28.  
20359198 R.S.Rowlett, K.M.Hoffmann, H.Failing, M.M.Mysliwiec, and D.Samardzic (2010).
Evidence for a bicarbonate "escort" site in Haemophilus influenzae beta-carbonic anhydrase .
  Biochemistry, 49, 3640-3647.
PDB codes: 3e2x 3e31 3e3f 3e3g 3e3i
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