4JX4

Structure of the carboxyl transferase domain from Rhizobium etli pyruvate carboxylase


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.98 Å
  • R-Value Free: 0.248 
  • R-Value Work: 0.214 
  • R-Value Observed: 0.216 

Starting Model: experimental
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wwPDB Validation   3D Report Full Report


This is version 1.4 of the entry. See complete history


Literature

A Substrate-induced Biotin Binding Pocket in the Carboxyltransferase Domain of Pyruvate Carboxylase.

Lietzan, A.D.St Maurice, M.

(2013) J Biol Chem 288: 19915-19925

  • DOI: https://doi.org/10.1074/jbc.M113.477828
  • Primary Citation of Related Structures:  
    4JX4, 4JX5, 4JX6

  • PubMed Abstract: 

    Biotin-dependent enzymes catalyze carboxyl transfer reactions by efficiently coordinating multiple reactions between spatially distinct active sites. Pyruvate carboxylase (PC), a multifunctional biotin-dependent enzyme, catalyzes the bicarbonate- and MgATP-dependent carboxylation of pyruvate to oxaloacetate, an important anaplerotic reaction in mammalian tissues. To complete the overall reaction, the tethered biotin prosthetic group must first gain access to the biotin carboxylase domain and become carboxylated and then translocate to the carboxyltransferase domain, where the carboxyl group is transferred from biotin to pyruvate. Here, we report structural and kinetic evidence for the formation of a substrate-induced biotin binding pocket in the carboxyltransferase domain of PC from Rhizobium etli. Structures of the carboxyltransferase domain reveal that R. etli PC occupies a symmetrical conformation in the absence of the biotin carboxylase domain and that the carboxyltransferase domain active site is conformationally rearranged upon pyruvate binding. This conformational change is stabilized by the interaction of the conserved residues Asp(590) and Tyr(628) and results in the formation of the biotin binding pocket. Site-directed mutations at these residues reduce the rate of biotin-dependent reactions but have no effect on the rate of biotin-independent oxaloacetate decarboxylation. Given the conservation with carboxyltransferase domains in oxaloacetate decarboxylase and transcarboxylase, the structure-based mechanism described for PC may be applicable to the larger family of biotin-dependent enzymes.


  • Organizational Affiliation

    Department of Biological Sciences, Marquette University, Milwaukee, Wisconsin 53201, USA.


Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Pyruvate carboxylase
A, B, C, D
632Rhizobium etli CFN 42Mutation(s): 0 
Gene Names: pycRHE_CH04002
EC: 6.4.1.1
UniProt
Find proteins for Q2K340 (Rhizobium etli (strain ATCC 51251 / DSM 11541 / JCM 21823 / NBRC 15573 / CFN 42))
Explore Q2K340 
Go to UniProtKB:  Q2K340
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupQ2K340
Sequence Annotations
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.98 Å
  • R-Value Free: 0.248 
  • R-Value Work: 0.214 
  • R-Value Observed: 0.216 
  • Space Group: P 21 21 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 86.211α = 90
b = 157.227β = 90
c = 245.144γ = 90
Software Package:
Software NamePurpose
MD2data collection
PHASERphasing
REFMACrefinement
DENZOdata reduction
SCALEPACKdata scaling

Structure Validation

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Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2013-05-29
    Type: Initial release
  • Version 1.1: 2013-06-19
    Changes: Database references
  • Version 1.2: 2013-07-24
    Changes: Database references
  • Version 1.3: 2023-09-20
    Changes: Data collection, Database references, Derived calculations, Refinement description
  • Version 1.4: 2023-12-06
    Changes: Data collection