4RZS

Lac repressor engineered to bind sucralose, unliganded tetramer


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.71 Å
  • R-Value Free: 0.239 
  • R-Value Work: 0.199 
  • R-Value Observed: 0.203 

wwPDB Validation   3D Report Full Report


This is version 1.3 of the entry. See complete history


Literature

Engineering an allosteric transcription factor to respond to new ligands.

Taylor, N.D.Garruss, A.S.Moretti, R.Chan, S.Arbing, M.A.Cascio, D.Rogers, J.K.Isaacs, F.J.Kosuri, S.Baker, D.Fields, S.Church, G.M.Raman, S.

(2016) Nat Methods 13: 177-183

  • DOI: 10.1038/nmeth.3696
  • Primary Citation of Related Structures:  
    4RZT, 4RZS

  • PubMed Abstract: 
  • Genetic regulatory proteins inducible by small molecules are useful synthetic biology tools as sensors and switches. Bacterial allosteric transcription factors (aTFs) are a major class of regulatory proteins, but few aTFs have been redesigned to respond to new effectors beyond natural aTF-inducer pairs ...

    Genetic regulatory proteins inducible by small molecules are useful synthetic biology tools as sensors and switches. Bacterial allosteric transcription factors (aTFs) are a major class of regulatory proteins, but few aTFs have been redesigned to respond to new effectors beyond natural aTF-inducer pairs. Altering inducer specificity in these proteins is difficult because substitutions that affect inducer binding may also disrupt allostery. We engineered an aTF, the Escherichia coli lac repressor, LacI, to respond to one of four new inducer molecules: fucose, gentiobiose, lactitol and sucralose. Using computational protein design, single-residue saturation mutagenesis or random mutagenesis, along with multiplex assembly, we identified new variants comparable in specificity and induction to wild-type LacI with its inducer, isopropyl β-D-1-thiogalactopyranoside (IPTG). The ability to create designer aTFs will enable applications including dynamic control of cell metabolism, cell biology and synthetic gene circuits.


    Organizational Affiliation

    Department of Genetics, Harvard Medical School, Boston, Massachusetts, USA.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
Lac repressorA, B, C, D381Escherichia coli DH1Mutation(s): 4 
Gene Names: b0345ECDH1ME8569_0332EcDH1_3261lacI
UniProt
Find proteins for P03023 (Escherichia coli (strain K12))
Explore P03023 
Go to UniProtKB:  P03023
Protein Feature View
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  • Reference Sequence
Small Molecules
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.71 Å
  • R-Value Free: 0.239 
  • R-Value Work: 0.199 
  • R-Value Observed: 0.203 
  • Space Group: P 21 21 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 91.09α = 90
b = 111.6β = 90
c = 189.33γ = 90
Software Package:
Software NamePurpose
XSCALEdata scaling
PHASERphasing
REFMACrefinement
PDB_EXTRACTdata extraction
XDSdata reduction

Structure Validation

View Full Validation Report



Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2015-12-23
    Type: Initial release
  • Version 1.1: 2016-01-06
    Changes: Database references
  • Version 1.2: 2016-03-02
    Changes: Database references
  • Version 1.3: 2017-11-22
    Changes: Refinement description