4UUO

Apo Trichomonas vaginalis malate dehydrogenase


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.842 Å
  • R-Value Free: 0.259 
  • R-Value Work: 0.206 

wwPDB Validation 3D Report Full Report


This is version 1.3 of the entry. See complete history

Literature

Gradual Neofunctionalization in the Convergent Evolution of Trichomonad Lactate and Malate Dehydrogenases.

Steindel, P.A.Chen, E.H.Wirth, J.D.Theobald, D.L.

(2016) Protein Sci. 25: 1319

  • DOI: 10.1002/pro.2904
  • Primary Citation of Related Structures:  4UUL, 4UUM, 4UUN, 4UUP, 5A1T

  • PubMed Abstract: 
  • Lactate and malate dehydrogenases (LDH and MDH) are homologous, core metabolic enzymes common to nearly all living organisms. LDHs have evolved convergently from MDHs at least four times, achieving altered substrate specificity by a different mechani ...

    Lactate and malate dehydrogenases (LDH and MDH) are homologous, core metabolic enzymes common to nearly all living organisms. LDHs have evolved convergently from MDHs at least four times, achieving altered substrate specificity by a different mechanism each time. For instance, the LDH of anaerobic trichomonad parasites recently evolved independently from an ancestral trichomonad MDH by gene duplication. LDH plays a central role in trichomonad metabolism by catalyzing the reduction of pyruvate to lactate, thereby regenerating the NAD+ required for glycolysis. Using ancestral reconstruction methods, we identified the biochemical and evolutionary mechanisms responsible for this convergent event. The last common ancestor of these enzymes was a highly specific MDH, similar to modern trichomonad MDHs. In contrast, the LDH lineage evolved promiscuous activity by relaxing specificity in a gradual process of neofunctionalization involving one highly detrimental substitution at the "specificity residue" (R91L) and many additional mutations of small effect. L91 has different functional consequences in LDHs and in MDHs, indicating a prominent role for epistasis. Crystal structures of modern-day and ancestral enzymes show that the evolution of substrate specificity paralleled structural changes in dimerization and α-helix orientation. The relatively small "specificity residue" of the trichomonad LDHs can accommodate a range of substrate sizes and may permit solvent to access the active site, both of which promote substrate promiscuity. The trichomonad LDHs present a multi-faceted counterpoint to the independent evolution of LDHs in other organisms and illustrate the diverse mechanisms by which protein function, structure, and stability coevolve.


    Organizational Affiliation

    Department of Biochemistry, Brandeis University, Waltham, Massachusetts, 02453.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
CYTOSOLIC MALATE DEHYDROGENASE
A
340Trichomonas vaginalisEC: 1.1.1.37
Find proteins for Q27819 (Trichomonas vaginalis)
Go to UniProtKB:  Q27819
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.842 Å
  • R-Value Free: 0.259 
  • R-Value Work: 0.206 
  • Space Group: I 21 3
Unit Cell:
Length (Å)Angle (°)
a = 155.000α = 90.00
b = 155.000β = 90.00
c = 155.000γ = 90.00
Software Package:
Software NamePurpose
PHENIXrefinement
XDSdata reduction
PHENIXphasing
XSCALEdata scaling

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2015-08-12
    Type: Initial release
  • Version 1.1: 2015-09-23
    Type: Data collection, Derived calculations, Refinement description
  • Version 1.2: 2016-03-02
    Type: Database references
  • Version 1.3: 2016-07-06
    Type: Database references