1W3U

Crystal structure of phosphoserine aminotransferase from Bacillus circulans var. alkalophilus


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.5 Å
  • R-Value Free: 0.208 

wwPDB Validation 3D Report Full Report


This is version 1.1 of the entry. See complete history

Literature

Enzyme Adaptation to Alkaline Ph: Atomic Resolution (1.08 A) Structure of Phosphoserine Aminotransferase from Bacillus Alcalophilus

Dubnovitsky, A.P.Kapetaniou, E.G.Papageorgiou, A.C.

(2005) Protein Sci. 14: 97

  • DOI: 10.1110/ps.041029805
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 
  • The crystal structure of the vitamin B(6)-dependent enzyme phosphoserine aminotransferase from the obligatory alkaliphile Bacillus alcalophilus has been determined at 1.08 A resolution. The model was refined to an R-factor of 11.7% (R(free) = 13.9%). ...

    The crystal structure of the vitamin B(6)-dependent enzyme phosphoserine aminotransferase from the obligatory alkaliphile Bacillus alcalophilus has been determined at 1.08 A resolution. The model was refined to an R-factor of 11.7% (R(free) = 13.9%). The enzyme displays a narrow pH optimum of enzymatic activity at pH 9.0. The final structure was compared to the previously reported structure of the mesophilic phosphoserine aminotransferase from Escherichia coli and to that of phosphoserine aminotransferase from a facultative alkaliphile, Bacillus circulans subsp. alkalophilus. All three enzymes are homodimers with each monomer comprising a two-domain architecture. Despite the high structural similarity, the alkaliphilic representatives possess a set of distinctive structural features. Two residues directly interacting with pyridoxal-5'-phosphate are replaced, and an additional hydrogen bond to the O3' atom of the cofactor is present in alkaliphilic phosphoserine aminotransferases. The number of hydrogen bonds and hydrophobic interactions at the dimer interface is increased. Hydrophobic interactions between the two domains in the monomers are enhanced. Moreover, the number of negatively charged amino acid residues increases on the solvent-accessible molecular surface and fewer hydrophobic residues are exposed to the solvent. Further, the total amount of ion pairs and ion networks is significantly reduced in the Bacillus enzymes, while the total number of hydrogen bonds is increased. The mesophilic enzyme from Escherichia coli contains two additional beta-strands in a surface loop with a third beta-strand being shorter in the structure. The identified structural features are proposed to be possible factors implicated in the alkaline adaptation of phosphoserine aminotransferase.


    Organizational Affiliation

    Turku Centre for Biotechnology, University of Turku, Finland.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
PHOSPHOSERINE AMINOTRANSFERASE
A
362Bacillus circulansMutation(s): 1 
Gene Names: serC
EC: 2.6.1.52
Find proteins for Q59196 (Bacillus circulans)
Go to UniProtKB:  Q59196
Small Molecules
Ligands 2 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
GOL
Query on GOL

Download SDF File 
Download CCD File 
A
GLYCEROL
GLYCERIN; PROPANE-1,2,3-TRIOL
C3 H8 O3
PEDCQBHIVMGVHV-UHFFFAOYSA-N
 Ligand Interaction
PLP
Query on PLP

Download SDF File 
Download CCD File 
A
PYRIDOXAL-5'-PHOSPHATE
VITAMIN B6 Phosphate
C8 H10 N O6 P
NGVDGCNFYWLIFO-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.5 Å
  • R-Value Free: 0.208 
  • Space Group: C 1 2 1
Unit Cell:
Length (Å)Angle (°)
a = 91.287α = 90.00
b = 91.109β = 111.25
c = 42.374γ = 90.00
Software Package:
Software NamePurpose
AMoREphasing
SCALEPACKdata scaling
DENZOdata reduction
SHELXL-97refinement

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2004-12-22
    Type: Initial release
  • Version 1.1: 2013-06-26
    Type: Database references, Derived calculations, Non-polymer description, Other, Structure summary, Version format compliance