5T7D

Crystal structure of Streptomyces hygroscopicus bialaphos resistance (BAR) protein in complex with acetyl coenzyme A

  • Classification: TRANSFERASE
  • Organism(s): Streptomyces hygroscopicus
  • Expression System: Escherichia coli BL21(DE3)

  • Deposited: 2016-09-04 Released: 2017-06-07 
  • Deposition Author(s): Christ, B., Weng, J.K.
  • Funding Organization(s): National Institutes of Health/National Institute of General Medical Sciences; NIH-ORIP HEI; Department of Energy (United States); Swiss National Science Foundation; Pew Scholar Program in the Biomedical Sciences; Searle Scholars Program 

Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.4 Å
  • R-Value Free: 0.192 
  • R-Value Work: 0.152 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Non-specific activities of the major herbicide-resistance gene BAR.

Christ, B.Hochstrasser, R.Guyer, L.Francisco, R.Aubry, S.Hortensteiner, S.Weng, J.K.

(2017) Nat Plants 3: 937-945

  • DOI: 10.1038/s41477-017-0061-1
  • Primary Citation of Related Structures:  5T7E

  • PubMed Abstract: 
  • Bialaphos resistance (BAR) and phosphinothricin acetyltransferase (PAT) genes, which convey resistance to the broad-spectrum herbicide phosphinothricin (also known as glufosinate) via N-acetylation, have been globally used in basic plant research and ...

    Bialaphos resistance (BAR) and phosphinothricin acetyltransferase (PAT) genes, which convey resistance to the broad-spectrum herbicide phosphinothricin (also known as glufosinate) via N-acetylation, have been globally used in basic plant research and genetically engineered crops 1-4 . Although early in vitro enzyme assays showed that recombinant BAR and PAT exhibit substrate preference toward phosphinothricin over the 20 proteinogenic amino acids 1 , indirect effects of BAR-containing transgenes in planta, including modified amino acid levels, have been seen but without the identification of their direct causes 5,6 . Combining metabolomics, plant genetics and biochemical approaches, we show that transgenic BAR indeed converts two plant endogenous amino acids, aminoadipate and tryptophan, to their respective N-acetylated products in several plant species. We report the crystal structures of BAR, and further delineate structural basis for its substrate selectivity and catalytic mechanism. Through structure-guided protein engineering, we generated several BAR variants that display significantly reduced non-specific activities compared with its wild-type counterpart in vivo. The transgenic expression of enzymes can result in unintended off-target metabolism arising from enzyme promiscuity. Understanding such phenomena at the mechanistic level can facilitate the design of maximally insulated systems featuring heterologously expressed enzymes.


    Organizational Affiliation

    Whitehead Institute for Biomedical Research, Cambridge, MA, 02142, USA.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Phosphinothricin N-acetyltransferase
A, B, C, D
189Streptomyces hygroscopicusGene Names: bar
EC: 2.3.1.183
Find proteins for P16426 (Streptomyces hygroscopicus)
Go to UniProtKB:  P16426
Small Molecules
Ligands 2 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
ACO
Query on ACO

Download SDF File 
Download CCD File 
A, B, C, D
ACETYL COENZYME *A
C23 H38 N7 O17 P3 S
ZSLZBFCDCINBPY-ZSJPKINUSA-N
 Ligand Interaction
ACT
Query on ACT

Download SDF File 
Download CCD File 
A, B, C, D
ACETATE ION
C2 H3 O2
QTBSBXVTEAMEQO-UHFFFAOYSA-M
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.4 Å
  • R-Value Free: 0.192 
  • R-Value Work: 0.152 
  • Space Group: P 1 21 1
Unit Cell:
Length (Å)Angle (°)
a = 65.100α = 90.00
b = 71.500β = 104.33
c = 84.050γ = 90.00
Software Package:
Software NamePurpose
PHENIXrefinement
SCALAdata scaling
PHASERphasing
iMOSFLMdata reduction

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History & Funding Information

Deposition Data

  • Deposited Date: 2016-09-04 
  • Released Date: 2017-06-07 
  • Deposition Author(s): Christ, B., Weng, J.K.

Funding OrganizationCountryGrant Number
National Institutes of Health/National Institute of General Medical SciencesUnited StatesP41 GM103403
NIH-ORIP HEIUnited StatesS10 RR029205
Department of Energy (United States)United StatesDE-AC02-06CH11357
Swiss National Science FoundationSwitzerlandP2ZHP3_155258
Pew Scholar Program in the Biomedical SciencesUnited States--
Searle Scholars ProgramUnited Arab Emirates--

Revision History 

  • Version 1.0: 2017-06-07
    Type: Initial release
  • Version 1.1: 2017-09-13
    Type: Author supporting evidence
  • Version 1.2: 2017-12-20
    Type: Database references