6SLH

Conformational flexibility within the small domain of human serine racemase.


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.89 Å
  • R-Value Free: 0.216 
  • R-Value Work: 0.172 

Starting Model: experimental
View more details

wwPDB Validation   3D Report Full Report


This is version 1.2 of the entry. See complete history


Literature

Conformational flexibility within the small domain of human serine racemase.

Koulouris, C.R.Bax, B.D.Atack, J.R.Roe, S.M.

(2020) Acta Crystallogr F Struct Biol Commun 76: 65-73

  • DOI: https://doi.org/10.1107/S2053230X20001193
  • Primary Citation of Related Structures:  
    6SLH

  • PubMed Abstract: 

    Serine racemase (SR) is a pyridoxal 5'-phosphate (PLP)-containing enzyme that converts L-serine to D-serine, an endogenous co-agonist for the N-methyl-D-aspartate receptor (NMDAR) subtype of glutamate ion channels. SR regulates D-serine levels by the reversible racemization of L-serine to D-serine, as well as the catabolism of serine by α,β-elimination to produce pyruvate. The modulation of SR activity is therefore an attractive therapeutic approach to disorders associated with abnormal glutamatergic signalling since it allows an indirect modulation of NMDAR function. In the present study, a 1.89 Å resolution crystal structure of the human SR holoenzyme (including the PLP cofactor) with four subunits in the asymmetric unit is described. Comparison of this new structure with the crystal structure of human SR with malonate (PDB entry 3l6b) shows an interdomain cleft that is open in the holo structure but which disappears when the inhibitor malonate binds and is enclosed. This is owing to a shift of the small domain (residues 78-155) in human SR similar to that previously described for the rat enzyme. This domain movement is accompanied by changes within the twist of the central four-stranded β-sheet of the small domain, including changes in the φ-ψ angles of all three residues in the C-terminal β-strand (residues 149-151). In the malonate-bound structure, Ser84 (a catalytic residue) points its side chain at the malonate and is preceded by a six-residue β-strand (residues 78-83), but in the holoenzyme the β-strand is only four residues (78-81) and His82 has φ-ψ values in the α-helical region of the Ramachandran plot. These data therefore represent a crystallographic platform that enables the structure-guided design of small-molecule modulators for this important but to date undrugged target.


  • Organizational Affiliation

    Sussex Drug Discovery Centre, University of Sussex, Falmer, Brighton BN1 9QG, England.


Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Serine racemaseA [auth AAA],
B [auth BBB],
C [auth CCC],
D [auth DDD]
346Homo sapiensMutation(s): 2 
Gene Names: SRR
EC: 5.1.1.18 (PDB Primary Data), 4.3.1.18 (PDB Primary Data), 4.3.1.17 (PDB Primary Data)
UniProt & NIH Common Fund Data Resources
Find proteins for Q9GZT4 (Homo sapiens)
Explore Q9GZT4 
Go to UniProtKB:  Q9GZT4
PHAROS:  Q9GZT4
GTEx:  ENSG00000167720 
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupQ9GZT4
Sequence Annotations
Expand
  • Reference Sequence
Small Molecules
Ligands 3 Unique
IDChains Name / Formula / InChI Key2D Diagram3D Interactions
PGE
Query on PGE

Download Ideal Coordinates CCD File 
E [auth AAA],
F [auth AAA],
N [auth BBB],
O [auth CCC]
TRIETHYLENE GLYCOL
C6 H14 O4
ZIBGPFATKBEMQZ-UHFFFAOYSA-N
MG
Query on MG

Download Ideal Coordinates CCD File 
G [auth AAA]
H [auth AAA]
M [auth BBB]
P [auth CCC]
Q [auth DDD]
G [auth AAA],
H [auth AAA],
M [auth BBB],
P [auth CCC],
Q [auth DDD],
R [auth DDD]
MAGNESIUM ION
Mg
JLVVSXFLKOJNIY-UHFFFAOYSA-N
NA
Query on NA

Download Ideal Coordinates CCD File 
I [auth AAA]
J [auth AAA]
K [auth AAA]
L [auth AAA]
S [auth DDD]
I [auth AAA],
J [auth AAA],
K [auth AAA],
L [auth AAA],
S [auth DDD],
T [auth DDD]
SODIUM ION
Na
FKNQFGJONOIPTF-UHFFFAOYSA-N
Modified Residues  1 Unique
IDChains TypeFormula2D DiagramParent
LLP
Query on LLP
A [auth AAA],
B [auth BBB],
C [auth CCC],
D [auth DDD]
L-PEPTIDE LINKINGC14 H22 N3 O7 PLYS
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.89 Å
  • R-Value Free: 0.216 
  • R-Value Work: 0.172 
  • Space Group: P 1 21 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 48.2α = 90
b = 155.74β = 98.48
c = 85.58γ = 90
Software Package:
Software NamePurpose
REFMACrefinement
xia2data reduction
xia2data scaling
PHENIXphasing

Structure Validation

View Full Validation Report



Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2020-02-12
    Type: Initial release
  • Version 1.1: 2020-02-19
    Changes: Database references
  • Version 1.2: 2024-01-24
    Changes: Data collection, Database references, Derived calculations, Refinement description