2EWH

Carboxysome protein CsoS1A from Halothiobacillus neapolitanus


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.40 Å
  • R-Value Free: 0.240 
  • R-Value Work: 0.185 
  • R-Value Observed: 0.187 

wwPDB Validation 3D Report Full Report


This is version 1.3 of the entry. See complete history


Literature

Structural Analysis of CsoS1A and the Protein Shell of the Halothiobacillus neapolitanus Carboxysome.

Tsai, Y.Sawaya, M.R.Cannon, G.C.Cai, F.Williams, E.B.Heinhorst, S.Kerfeld, C.A.Yeates, T.O.

(2007) PLoS Biol 5: e144

  • DOI: 10.1371/journal.pbio.0050144
  • Structures With Same Primary Citation

  • PubMed Abstract: 
  • The carboxysome is a bacterial organelle that functions to enhance the efficiency of CO2 fixation by encapsulating the enzymes ribulose bisphosphate carboxylase/oxygenase (RuBisCO) and carbonic anhydrase. The outer shell of the carboxysome is reminis ...

    The carboxysome is a bacterial organelle that functions to enhance the efficiency of CO2 fixation by encapsulating the enzymes ribulose bisphosphate carboxylase/oxygenase (RuBisCO) and carbonic anhydrase. The outer shell of the carboxysome is reminiscent of a viral capsid, being constructed from many copies of a few small proteins. Here we describe the structure of the shell protein CsoS1A from the chemoautotrophic bacterium Halothiobacillus neapolitanus. The CsoS1A protein forms hexameric units that pack tightly together to form a molecular layer, which is perforated by narrow pores. Sulfate ions, soaked into crystals of CsoS1A, are observed in the pores of the molecular layer, supporting the idea that the pores could be the conduit for negatively charged metabolites such as bicarbonate, which must cross the shell. The problem of diffusion across a semiporous protein shell is discussed, with the conclusion that the shell is sufficiently porous to allow adequate transport of small molecules. The molecular layer formed by CsoS1A is similar to the recently observed layers formed by cyanobacterial carboxysome shell proteins. This similarity supports the argument that the layers observed represent the natural structure of the facets of the carboxysome shell. Insights into carboxysome function are provided by comparisons of the carboxysome shell to viral capsids, and a comparison of its pores to the pores of transmembrane protein channels.


    Organizational Affiliation

    Molecular Biology Institute, University of California Los Angeles, Los Angeles, California, United States of America.



Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Major carboxysome shell protein 1AA98Halothiobacillus neapolitanusMutation(s): 0 
Gene Names: csoS1A
Find proteins for P45689 (Halothiobacillus neapolitanus (strain ATCC 23641 / c2))
Explore P45689 
Go to UniProtKB:  P45689
Protein Feature View
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  • Reference Sequence
Small Molecules
Ligands 2 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
TRS
Query on TRS

Download CCD File 
A
2-AMINO-2-HYDROXYMETHYL-PROPANE-1,3-DIOL
C4 H12 N O3
LENZDBCJOHFCAS-UHFFFAOYSA-O
 Ligand Interaction
EDO
Query on EDO

Download CCD File 
A
1,2-ETHANEDIOL
C2 H6 O2
LYCAIKOWRPUZTN-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.40 Å
  • R-Value Free: 0.240 
  • R-Value Work: 0.185 
  • R-Value Observed: 0.187 
  • Space Group: P 6
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 66.417α = 90
b = 66.417β = 90
c = 28.982γ = 120
Software Package:
Software NamePurpose
DENZOdata reduction
SCALEPACKdata scaling
PHASERphasing
REFMACrefinement
PDB_EXTRACTdata extraction
BOSdata collection

Structure Validation

View Full Validation Report



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2006-11-14
    Type: Initial release
  • Version 1.1: 2008-05-01
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Advisory, Derived calculations, Version format compliance
  • Version 1.3: 2017-10-18
    Changes: Refinement description