Structure and function of aldehyde dehydrogenase from Thermus thermophilus: An enzyme with an evolutionarily-distinct C-terminal arm (Native protein)

Experimental Data Snapshot

  • Resolution: 2.25 Å
  • R-Value Free: 0.210 
  • R-Value Work: 0.189 
  • R-Value Observed: 0.189 

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This is version 2.2 of the entry. See complete history


The quaternary structure of Thermus thermophilus aldehyde dehydrogenase is stabilized by an evolutionary distinct C-terminal arm extension.

Hayes, K.Noor, M.Djeghader, A.Armshaw, P.Pembroke, T.Tofail, S.Soulimane, T.

(2018) Sci Rep 8: 13327-13327

  • DOI: https://doi.org/10.1038/s41598-018-31724-8
  • Primary Citation of Related Structures:  
    6FJX, 6FK3, 6FKU, 6FKV

  • PubMed Abstract: 

    Aldehyde dehydrogenases (ALDH) form a superfamily of dimeric or tetrameric enzymes that catalyze the oxidation of a broad range of aldehydes into their corresponding carboxylic acids with the concomitant reduction of the cofactor NAD(P) into NAD(P)H. Despite their varied polypeptide chain length and oligomerisation states, ALDHs possess a conserved architecture of three domains: the catalytic domain, NAD(P) + binding domain, and the oligomerization domain. Here, we describe the structure and function of the ALDH from Thermus thermophilus (ALDH Tt ) which exhibits non-canonical features of both dimeric and tetrameric ALDH and a previously uncharacterized C-terminal arm extension forming novel interactions with the N-terminus in the quaternary structure. This unusual tail also interacts closely with the substrate entry tunnel in each monomer providing further mechanistic detail for the recent discovery of tail-mediated activity regulation in ALDH. However, due to the novel distal extension of the tail of ALDH Tt and stabilizing termini-interactions, the current model of tail-mediated substrate access is not apparent in ALDH Tt . The discovery of such a long tail in a deeply and early branching phylum such as Deinococcus-Thermus indicates that ALDH Tt may be an ancestral or primordial metabolic model of study. This structure provides invaluable evidence of how metabolic regulation has evolved and provides a link to early enzyme regulatory adaptations.

  • Organizational Affiliation

    Department of Chemical Sciences, University of Limerick, Limerick, V94 T9PX, Ireland.

Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Aldehyde dehydrogenase
A, B
530Thermus thermophilus HB27Mutation(s): 0 
Find proteins for Q72KD3 (Thermus thermophilus (strain ATCC BAA-163 / DSM 7039 / HB27))
Explore Q72KD3 
Go to UniProtKB:  Q72KD3
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupQ72KD3
Sequence Annotations
  • Reference Sequence
Small Molecules
Ligands 3 Unique
IDChains Name / Formula / InChI Key2D Diagram3D Interactions
Query on BOG

Download Ideal Coordinates CCD File 
D [auth A],
G [auth B]
octyl beta-D-glucopyranoside
C14 H28 O6
Query on PGE

Download Ideal Coordinates CCD File 
C6 H14 O4
Query on SO4

Download Ideal Coordinates CCD File 
E [auth A]
F [auth A]
H [auth B]
I [auth B]
J [auth B]
E [auth A],
F [auth A],
H [auth B],
I [auth B],
J [auth B],
K [auth B]
O4 S
Experimental Data & Validation

Experimental Data

  • Resolution: 2.25 Å
  • R-Value Free: 0.210 
  • R-Value Work: 0.189 
  • R-Value Observed: 0.189 
  • Space Group: P 41 21 2
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 105.29α = 90
b = 105.29β = 90
c = 314.45γ = 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: 2018-09-26
    Type: Initial release
  • Version 2.0: 2018-12-19
    Changes: Atomic model, Data collection, Derived calculations
  • Version 2.1: 2020-07-29
    Type: Remediation
    Reason: Carbohydrate remediation
    Changes: Data collection, Derived calculations, Structure summary
  • Version 2.2: 2024-01-17
    Changes: Data collection, Database references, Refinement description, Structure summary