Structure of the A-PCP didomain of carboxylic acid reductase (CAR) from Segniliparus rugosus in complex with AMP

Experimental Data Snapshot

  • Resolution: 1.96 Å
  • R-Value Free: 0.254 
  • R-Value Work: 0.204 
  • R-Value Observed: 0.207 

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Structures of carboxylic acid reductase reveal domain dynamics underlying catalysis.

Gahloth, D.Dunstan, M.S.Quaglia, D.Klumbys, E.Lockhart-Cairns, M.P.Hill, A.M.Derrington, S.R.Scrutton, N.S.Turner, N.J.Leys, D.

(2017) Nat Chem Biol 13: 975-981

  • DOI: https://doi.org/10.1038/nchembio.2434
  • Primary Citation of Related Structures:  
    5MSC, 5MSD, 5MSO, 5MSP, 5MSR, 5MSS, 5MST, 5MSU, 5MSV, 5MSW

  • PubMed Abstract: 

    Carboxylic acid reductase (CAR) catalyzes the ATP- and NADPH-dependent reduction of carboxylic acids to the corresponding aldehydes. The enzyme is related to the nonribosomal peptide synthetases, consisting of an adenylation domain fused via a peptidyl carrier protein (PCP) to a reductase termination domain. Crystal structures of the CAR adenylation-PCP didomain demonstrate that large-scale domain motions occur between the adenylation and thiolation states. Crystal structures of the PCP-reductase didomain reveal that phosphopantetheine binding alters the orientation of a key Asp, resulting in a productive orientation of the bound nicotinamide. This ensures that further reduction of the aldehyde product does not occur. Combining crystallography with small-angle X-ray scattering (SAXS), we propose that molecular interactions between initiation and termination domains are limited to competing PCP docking sites. This theory is supported by the fact that (R)-pantetheine can support CAR activity for mixtures of the isolated domains. Our model suggests directions for further development of CAR as a biocatalyst.

  • Organizational Affiliation

    Manchester Institute of Biotechnology, School of Chemistry, University of Manchester, Manchester, UK.

Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Thioester reductase domain-containing protein1,188Segniliparus rugosus ATCC BAA-974Mutation(s): 0 
Gene Names: HMPREF9336_01297
Find proteins for E5XP76 (Segniliparus rugosus (strain ATCC BAA-974 / DSM 45345 / CCUG 50838 / CIP 108380 / JCM 13579 / CDC 945))
Explore E5XP76 
Go to UniProtKB:  E5XP76
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupE5XP76
Sequence Annotations
  • Reference Sequence
Small Molecules
Ligands 2 Unique
IDChains Name / Formula / InChI Key2D Diagram3D Interactions
Query on AMP

Download Ideal Coordinates CCD File 
C10 H14 N5 O7 P
Query on NA

Download Ideal Coordinates CCD File 
Experimental Data & Validation

Experimental Data

  • Resolution: 1.96 Å
  • R-Value Free: 0.254 
  • R-Value Work: 0.204 
  • R-Value Observed: 0.207 
  • Space Group: C 2 2 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 59.719α = 90
b = 127.693β = 90
c = 212.244γ = 90
Software Package:
Software NamePurpose
XDSdata reduction
XDSdata scaling

Structure Validation

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Ligand Structure Quality Assessment 

Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2017-07-05
    Type: Initial release
  • Version 1.1: 2017-07-12
    Changes: Database references
  • Version 1.2: 2017-07-26
    Changes: Database references, Structure summary
  • Version 1.3: 2017-08-30
    Changes: Database references
  • Version 1.4: 2024-01-17
    Changes: Data collection, Database references, Refinement description