4QUK

Crystal Structure of Cinnamyl-Alcohol Dehydrogenase 2 Mutant K169A


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.90 Å
  • R-Value Free: 0.225 
  • R-Value Work: 0.185 
  • R-Value Observed: 0.185 

wwPDB Validation 3D Report Full Report


This is version 1.1 of the entry. See complete history


Literature

Structural Studies of Cinnamoyl-CoA Reductase and Cinnamyl-Alcohol Dehydrogenase, Key Enzymes of Monolignol Biosynthesis.

Pan, H.Zhou, R.Louie, G.V.Muhlemann, J.K.Bomati, E.K.Bowman, M.E.Dudareva, N.Dixon, R.A.Noel, J.P.Wang, X.

(2014) Plant Cell 26: 3709-3727

  • DOI: 10.1105/tpc.114.127399
  • Structures With Same Primary Citation

  • PubMed Abstract: 
  • The enzymes cinnamoyl-CoA reductase (CCR) and cinnamyl alcohol dehydrogenase (CAD) catalyze the two key reduction reactions in the conversion of cinnamic acid derivatives into monolignol building blocks for lignin polymers in plant cell walls. Here, ...

    The enzymes cinnamoyl-CoA reductase (CCR) and cinnamyl alcohol dehydrogenase (CAD) catalyze the two key reduction reactions in the conversion of cinnamic acid derivatives into monolignol building blocks for lignin polymers in plant cell walls. Here, we describe detailed functional and structural analyses of CCRs from Medicago truncatula and Petunia hybrida and of an atypical CAD (CAD2) from M. truncatula. These enzymes are closely related members of the short-chain dehydrogenase/reductase (SDR) superfamily. Our structural studies support a reaction mechanism involving a canonical SDR catalytic triad in both CCR and CAD2 and an important role for an auxiliary cysteine unique to CCR. Site-directed mutants of CAD2 (Phe226Ala and Tyr136Phe) that enlarge the phenolic binding site result in a 4- to 10-fold increase in activity with sinapaldehyde, which in comparison to the smaller coumaraldehyde and coniferaldehyde substrates is disfavored by wild-type CAD2. This finding demonstrates the potential exploitation of rationally engineered forms of CCR and CAD2 for the targeted modification of monolignol composition in transgenic plants. Thermal denaturation measurements and structural comparisons of various liganded and unliganded forms of CCR and CAD2 highlight substantial conformational flexibility of these SDR enzymes, which plays an important role in the establishment of catalytically productive complexes of the enzymes with their NADPH and phenolic substrates.


    Organizational Affiliation

    Plant Biology Division, Samuel Roberts Noble Foundation, Ardmore, Oklahoma 73401 xiaoqiang.wang@unt.edu.



Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Dihydroflavonol-4-reductase
A
319Medicago truncatulaMutation(s): 1 
Gene Names: MTR_3g00517011427940MtrunA17_Chr3g0077221
EC: 1.1.1 (PDB Primary Data), 1.1.1.195 (UniProt)
Find proteins for G7IYC1 (Medicago truncatula)
Go to UniProtKB:  G7IYC1
Protein Feature View
  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.90 Å
  • R-Value Free: 0.225 
  • R-Value Work: 0.185 
  • R-Value Observed: 0.185 
  • Space Group: P 21 21 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 37.797α = 90
b = 76.565β = 90
c = 106.045γ = 90
Software Package:
Software NamePurpose
CrystalCleardata collection
CNSrefinement
HKL-2000data reduction
HKL-2000data scaling
CNSphasing

Structure Validation

View Full Validation Report



Entry History 

Deposition Data

  • Deposited Date: 2014-07-10 
  • Released Date: 2014-10-01 
  • Deposition Author(s): Pan, H., Wang, X.

Revision History 

  • Version 1.0: 2014-10-01
    Type: Initial release
  • Version 1.1: 2014-11-12
    Changes: Database references