4CVQ

CRYSTAL STRUCTURE OF AN AMINOTRANSFERASE FROM ESCHERICHIA COLI AT 2. 11 ANGSTROEM RESOLUTION


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.11 Å
  • R-Value Free: 0.247 
  • R-Value Work: 0.204 
  • R-Value Observed: 0.206 

wwPDB Validation   3D Report Full Report


This is version 1.1 of the entry. See complete history


Literature

Structural analysis and mutant growth properties reveal distinctive enzymatic and cellular roles for the three major L-alanine transaminases of Escherichia coli.

Pena-Soler, E.Fernandez, F.J.Lopez-Estepa, M.Garces, F.Richardson, A.J.Quintana, J.F.Rudd, K.E.Coll, M.Vega, M.C.

(2014) PLoS One 9: e102139-e102139

  • DOI: 10.1371/journal.pone.0102139
  • Primary Citation of Related Structures:  
    4CVQ

  • PubMed Abstract: 
  • In order to maintain proper cellular function, the metabolism of the bacterial microbiota presents several mechanisms oriented to keep a correctly balanced amino acid pool. Central components of these mechanisms are enzymes with alanine transaminase activity, pyridoxal 5'-phosphate-dependent enzymes that interconvert alanine and pyruvate, thereby allowing the precise control of alanine and glutamate concentrations, two of the most abundant amino acids in the cellular amino acid pool ...

    In order to maintain proper cellular function, the metabolism of the bacterial microbiota presents several mechanisms oriented to keep a correctly balanced amino acid pool. Central components of these mechanisms are enzymes with alanine transaminase activity, pyridoxal 5'-phosphate-dependent enzymes that interconvert alanine and pyruvate, thereby allowing the precise control of alanine and glutamate concentrations, two of the most abundant amino acids in the cellular amino acid pool. Here we report the 2.11-Å crystal structure of full-length AlaA from the model organism Escherichia coli, a major bacterial alanine aminotransferase, and compare its overall structure and active site composition with detailed atomic models of two other bacterial enzymes capable of catalyzing this reaction in vivo, AlaC and valine-pyruvate aminotransferase (AvtA). Apart from a narrow entry channel to the active site, a feature of this new crystal structure is the role of an active site loop that closes in upon binding of substrate-mimicking molecules, and which has only been previously reported in a plant enzyme. Comparison of the available structures indicates that beyond superficial differences, alanine aminotransferases of diverse phylogenetic origins share a universal reaction mechanism that depends on an array of highly conserved amino acid residues and is similarly regulated by various unrelated motifs. Despite this unifying mechanism and regulation, growth competition experiments demonstrate that AlaA, AlaC and AvtA are not freely exchangeable in vivo, suggesting that their functional repertoire is not completely redundant thus providing an explanation for their independent evolutionary conservation.


    Organizational Affiliation

    Centro de Investigaciones Biológicas, Consejo Superior de Investigaciones Científicas (Spanish National Research Council, CSIC), Madrid, Spain.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
GLUTAMATE-PYRUVATE AMINOTRANSFERASE ALAAA, B431Escherichia coli K-12Mutation(s): 0 
Gene Names: alaAyfbQb2290JW2287
EC: 2.6.1.2
UniProt
Find proteins for P0A959 (Escherichia coli (strain K12))
Explore P0A959 
Go to UniProtKB:  P0A959
Protein Feature View
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  • Reference Sequence
Small Molecules
Ligands 3 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
PLP
Query on PLP

Download Ideal Coordinates CCD File 
C [auth A], E [auth B]PYRIDOXAL-5'-PHOSPHATE
C8 H10 N O6 P
NGVDGCNFYWLIFO-UHFFFAOYSA-N
 Ligand Interaction
GOL
Query on GOL

Download Ideal Coordinates CCD File 
G [auth B]GLYCEROL
C3 H8 O3
PEDCQBHIVMGVHV-UHFFFAOYSA-N
 Ligand Interaction
ACT
Query on ACT

Download Ideal Coordinates CCD File 
D [auth A], F [auth B]ACETATE ION
C2 H3 O2
QTBSBXVTEAMEQO-UHFFFAOYSA-M
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.11 Å
  • R-Value Free: 0.247 
  • R-Value Work: 0.204 
  • R-Value Observed: 0.206 
  • Space Group: C 2 2 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 59.78α = 90
b = 152.13β = 90
c = 174.24γ = 90
Software Package:
Software NamePurpose
PHENIXrefinement
XDSdata reduction
SCALAdata scaling
AMoREphasing

Structure Validation

View Full Validation Report



Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2014-07-23
    Type: Initial release
  • Version 1.1: 2017-08-09
    Changes: Database references