Candida albicans seryl-tRNA synthetase

Experimental Data Snapshot

  • Resolution: 2.00 Å
  • R-Value Free: 0.206 
  • R-Value Work: 0.165 
  • R-Value Observed: 0.167 

wwPDB Validation   3D Report Full Report

This is version 1.5 of the entry. See complete history


Unveiling the structural basis for translational ambiguity tolerance in a human fungal pathogen.

Rocha, R.Pereira, P.J.Santos, M.A.Macedo-Ribeiro, S.

(2011) Proc Natl Acad Sci U S A 108: 14091-14096

  • DOI: https://doi.org/10.1073/pnas.1102835108
  • Primary Citation of Related Structures:  
    3QNE, 3QO5, 3QO7, 3QO8

  • PubMed Abstract: 

    In a restricted group of opportunistic fungal pathogens the universal leucine CUG codon is translated both as serine (97%) and leucine (3%), challenging the concept that translational ambiguity has a negative impact in living organisms. To elucidate the molecular mechanisms underlying the in vivo tolerance to a nonconserved genetic code alteration, we have undertaken an extensive structural analysis of proteins containing CUG-encoded residues and solved the crystal structures of the two natural isoforms of Candida albicans seryl-tRNA synthetase. We show that codon reassignment resulted in a nonrandom genome-wide CUG redistribution tailored to minimize protein misfolding events induced by the large-scale leucine-to-serine replacement within the CTG clade. Leucine or serine incorporation at the CUG position in C. albicans seryl-tRNA synthetase induces only local structural changes and, although both isoforms display tRNA serylation activity, the leucine-containing isoform is more active. Similarly, codon ambiguity is predicted to shape the function of C. albicans proteins containing CUG-encoded residues in functionally relevant positions, some of which have a key role in signaling cascades associated with morphological changes and pathogenesis. This study provides a first detailed analysis on natural reassignment of codon identity, unveiling a highly dynamic evolutionary pattern of thousands of fungal CUG codons to confer an optimized balance between protein structural robustness and functional plasticity.

  • Organizational Affiliation

    Instituto de Biologia Molecular e Celular, Universidade do Porto, 4150-180 Porto, Portugal.

Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Seryl-tRNA synthetase, cytoplasmic485Candida albicansMutation(s): 0 
Gene Names: CaO19.7901SES1
Find proteins for Q9HGT6 (Candida albicans (strain SC5314 / ATCC MYA-2876))
Explore Q9HGT6 
Go to UniProtKB:  Q9HGT6
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupQ9HGT6
Sequence Annotations
  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Resolution: 2.00 Å
  • R-Value Free: 0.206 
  • R-Value Work: 0.165 
  • R-Value Observed: 0.167 
  • Space Group: P 61 2 2
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 90.05α = 90
b = 90.05β = 90
c = 276.757γ = 120
Software Package:
Software NamePurpose
ADSCdata collection
MOSFLMdata reduction
SCALAdata scaling

Structure Validation

View Full Validation Report

Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2011-08-03
    Type: Initial release
  • Version 1.1: 2011-08-24
    Changes: Database references
  • Version 1.2: 2011-08-31
    Changes: Database references
  • Version 1.3: 2011-09-14
    Changes: Database references
  • Version 1.4: 2014-09-10
    Changes: Database references
  • Version 1.5: 2023-09-13
    Changes: Data collection, Database references, Refinement description