5WXX

Crystal structure of Microcystis aeruginosa PCC 7806 aspartate racemase in complex with citrate


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.35 Å
  • R-Value Free: 0.202 
  • R-Value Work: 0.187 
  • R-Value Observed: 0.187 

wwPDB Validation   3D Report Full Report


This is version 1.1 of the entry. See complete history


Literature

Structural insights into the catalysis and substrate specificity of cyanobacterial aspartate racemase McyF.

Cao, D.D.Zhang, C.P.Zhou, K.Jiang, Y.L.Tan, X.F.Xie, J.Ren, Y.M.Chen, Y.Zhou, C.Z.Hou, W.T.

(2019) Biochem Biophys Res Commun 514: 1108-1114

  • DOI: https://doi.org/10.1016/j.bbrc.2019.05.063
  • Primary Citation of Related Structures:  
    5WXX, 5WXY, 5WXZ

  • PubMed Abstract: 

    L-amino acids represent the most common amino acid form, most notably as protein residues, whereas D-amino acids, despite their rare occurrence, play significant roles in many biological processes. Amino acid racemases are enzymes that catalyze the interconversion of L- and/or D-amino acids. McyF is a pyridoxal 5'-phosphate (PLP) independent amino acid racemase that produces the substrate D-aspartate for the biosynthesis of microcystin in the cyanobacterium Microcystis aeruginosa PCC7806. Here we report the crystal structures of McyF in complex with citrate, L-Asp and D-Asp at 2.35, 2.63 and 2.80 Å, respectively. Structural analyses indicate that McyF and homologs possess highly conserved residues involved in substrate binding and catalysis. In addition, residues Cys87 and Cys195 were clearly assigned to the key catalytic residues of "two bases" that deprotonate D-Asp and L-Asp in a reaction independent of PLP. Further site-directed mutagenesis combined with enzymatic assays revealed that Glu197 also participates in the catalytic reaction. In addition, activity assays proved that McyF could also catalyze the interconversion of L-MeAsp between D-MeAsp, the precursor of another microcystin isoform. These findings provide structural insights into the catalytic mechanism of aspartate racemase and microcystin biosynthesis.


  • Organizational Affiliation

    Hefei National Laboratory for Physical Sciences at the Microscale and School of Life Sciences, University of Science and Technology of China, Hefei Anhui 230027, China.


Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
McyF260Microcystis aeruginosa PCC 7806Mutation(s): 0 
Gene Names: mcyFIPF_371
UniProt
Find proteins for Q9RNB4 (Microcystis aeruginosa (strain PCC 7806))
Explore Q9RNB4 
Go to UniProtKB:  Q9RNB4
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupQ9RNB4
Sequence Annotations
Expand
  • Reference Sequence
Small Molecules
Ligands 1 Unique
IDChains Name / Formula / InChI Key2D Diagram3D Interactions
CIT
Query on CIT

Download Ideal Coordinates CCD File 
B [auth A]CITRIC ACID
C6 H8 O7
KRKNYBCHXYNGOX-UHFFFAOYSA-N
Modified Residues  1 Unique
IDChains TypeFormula2D DiagramParent
MSE
Query on MSE
A
L-PEPTIDE LINKINGC5 H11 N O2 SeMET
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.35 Å
  • R-Value Free: 0.202 
  • R-Value Work: 0.187 
  • R-Value Observed: 0.187 
  • Space Group: P 32 2 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 128.751α = 90
b = 128.751β = 90
c = 46.182γ = 120
Software Package:
Software NamePurpose
REFMACrefinement
HKL-2000data reduction
HKL-2000data scaling
PHENIXphasing

Structure Validation

View Full Validation Report



Entry History & Funding Information

Deposition Data


Funding OrganizationLocationGrant Number
National Natural Science Foundation of ChinaChina31630001
National Natural Science Foundation of ChinaChina31370757
National Natural Science Foundation of ChinaChina31500602
Ministry of Education of ChinaChina20133402110023

Revision History  (Full details and data files)

  • Version 1.0: 2018-01-17
    Type: Initial release
  • Version 1.1: 2019-07-31
    Changes: Data collection, Database references