Crystal structure of a mitochondrial ornithine carbamoyltransferase from Coccidioides immitis

Experimental Data Snapshot

  • Resolution: 2.80 Å
  • R-Value Free: 0.239 
  • R-Value Work: 0.193 
  • R-Value Observed: 0.195 

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Expression of proteins in Escherichia coli as fusions with maltose-binding protein to rescue non-expressed targets in a high-throughput protein-expression and purification pipeline.

Hewitt, S.N.Choi, R.Kelley, A.Crowther, G.J.Napuli, A.J.Van Voorhis, W.C.

(2011) Acta Crystallogr Sect F Struct Biol Cryst Commun 67: 1006-1009

  • DOI: https://doi.org/10.1107/S1744309111022159
  • Primary Citation of Related Structures:  
    3SDS, 3TL6, 3U40

  • PubMed Abstract: 

    Despite recent advances, the expression of heterologous proteins in Escherichia coli for crystallization remains a nontrivial challenge. The present study investigates the efficacy of maltose-binding protein (MBP) fusion as a general strategy for rescuing the expression of target proteins. From a group of sequence-verified clones with undetectable levels of protein expression in an E. coli T7 expression system, 95 clones representing 16 phylogenetically diverse organisms were selected for recloning into a chimeric expression vector with an N-terminal histidine-tagged MBP. PCR-amplified inserts were annealed into an identical ligation-independent cloning region in an MBP-fusion vector and were analyzed for expression and solubility by high-throughput nickel-affinity binding. This approach yielded detectable expression of 72% of the clones; soluble expression was visible in 62%. However, the solubility of most proteins was marginal to poor upon cleavage of the MBP tag. This study offers large-scale evidence that MBP can improve the soluble expression of previously non-expressing proteins from a variety of eukaryotic and prokaryotic organisms. While the behavior of the cleaved proteins was disappointing, further refinements in MBP tagging may permit the more widespread use of MBP-fusion proteins in crystallographic studies.

  • Organizational Affiliation

    Seattle Structural Genomics Center for Infectious Disease (SSGCID), University of Washington, WA 98195, USA.

Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Ornithine carbamoyltransferase, mitochondrial
A, B, C
353Coccidioides immitis RSMutation(s): 0 
Gene Names: CIMG_04084
Find proteins for P0CL21 (Coccidioides immitis (strain RS))
Explore P0CL21 
Go to UniProtKB:  P0CL21
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP0CL21
Sequence Annotations
  • Reference Sequence
Experimental Data & Validation

Experimental Data

Unit Cell:
Length ( Å )Angle ( ˚ )
a = 150.36α = 90
b = 150.36β = 90
c = 92.11γ = 120
Software Package:
Software NamePurpose
XSCALEdata scaling
PDB_EXTRACTdata extraction
XDSdata reduction

Structure Validation

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Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2011-06-22
    Type: Initial release
  • Version 1.1: 2011-07-13
    Changes: Version format compliance
  • Version 1.2: 2011-09-21
    Changes: Database references
  • Version 1.3: 2024-02-28
    Changes: Data collection, Database references, Derived calculations