2I49

Crystal structure of apo form of Bicarbonate Transport Protein CmpA from Synechocystis sp. PCC 6803


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.35 Å
  • R-Value Free: 0.193 
  • R-Value Work: 0.178 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

The Structure of a Cyanobacterial Bicarbonate Transport Protein, CmpA.

Koropatkin, N.M.Koppenaal, D.W.Pakrasi, H.B.Smith, T.J.

(2007) J.Biol.Chem. 282: 2606-2614

  • DOI: 10.1074/jbc.M610222200
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 
  • Cyanobacteria, blue-green algae, are the most abundant autotrophs in aquatic environments and form the base of the food chain by fixing carbon and nitrogen into cellular biomass. To compensate for the low selectivity of Rubisco for CO2 over O2, cyano ...

    Cyanobacteria, blue-green algae, are the most abundant autotrophs in aquatic environments and form the base of the food chain by fixing carbon and nitrogen into cellular biomass. To compensate for the low selectivity of Rubisco for CO2 over O2, cyanobacteria have developed highly efficient CO2-concentrating machinery of which the ABC transport system CmpABCD from Synechocystis PCC 6803 is one component. Here, we have described the structure of the bicarbonate-binding protein CmpA in the absence and presence of bicarbonate and carbonic acid. CmpA is highly homologous to the nitrate transport protein NrtA. CmpA binds carbonic acid at the entrance to the ligand-binding pocket, whereas bicarbonate binds in nearly an identical location compared with nitrate binding to NrtA. Unexpectedly, bicarbonate binding is accompanied by a metal ion, identified as Ca2+ via inductively coupled plasma optical emission spectrometry. The binding of bicarbonate and metal appears to be highly cooperative and suggests that CmpA may co-transport bicarbonate and calcium or that calcium acts a cofactor in bicarbonate transport.


    Organizational Affiliation

    Donald Danforth Plant Science Center, St. Louis, Missouri 63132, USA.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Bicarbonate transporter
A
429Synechocystis sp. (strain PCC 6803 / Kazusa)Mutation(s): 0 
Gene Names: cmpA
Find proteins for Q55460 (Synechocystis sp. (strain PCC 6803 / Kazusa))
Go to UniProtKB:  Q55460
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.35 Å
  • R-Value Free: 0.193 
  • R-Value Work: 0.178 
  • Space Group: P 1
Unit Cell:
Length (Å)Angle (°)
a = 44.660α = 87.57
b = 49.680β = 81.20
c = 57.570γ = 75.20
Software Package:
Software NamePurpose
PROTEUM PLUSdata scaling
AMoREphasing
SAINTdata reduction
PROTEUM PLUSdata collection
PDB_EXTRACTdata extraction
CNSrefinement

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2006-12-19
    Type: Initial release
  • Version 1.1: 2008-05-01
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Source and taxonomy, Version format compliance