6ESL

Crystal structure of the Legionella pneumoppila LapA


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.87 Å
  • R-Value Free: 0.238 
  • R-Value Work: 0.192 
  • R-Value Observed: 0.195 

wwPDB Validation   3D Report Full Report


This is version 1.1 of the entry. See complete history


Literature

Type II Secretion-Dependent Aminopeptidase LapA and Acyltransferase PlaC Are Redundant for Nutrient Acquisition duringLegionella pneumophilaIntracellular Infection of Amoebas.

White, R.C.Gunderson, F.F.Tyson, J.Y.Richardson, K.H.Portlock, T.J.Garnett, J.A.Cianciotto, N.P.

(2018) mBio 9

  • DOI: 10.1128/mBio.00528-18
  • Primary Citation of Related Structures:  
    6ESL

  • PubMed Abstract: 
  • Legionella pneumophila genes encoding LapA, LapB, and PlaC were identified as the most highly upregulated type II secretion (T2S) genes during infection of Acanthamoeba castellanii , although these genes had been considered dispensable on the basis of the behavior of mutants lacking either lapA and lapB or plaC A plaC mutant showed even higher levels of lapA and lapB transcripts, and a lapA lapB mutant showed heightening of plaC mRNA levels, suggesting that the role of the LapA/B aminopeptidase is compensatory with respect to that of the PlaC acyltransferase ...

    Legionella pneumophila genes encoding LapA, LapB, and PlaC were identified as the most highly upregulated type II secretion (T2S) genes during infection of Acanthamoeba castellanii , although these genes had been considered dispensable on the basis of the behavior of mutants lacking either lapA and lapB or plaC A plaC mutant showed even higher levels of lapA and lapB transcripts, and a lapA lapB mutant showed heightening of plaC mRNA levels, suggesting that the role of the LapA/B aminopeptidase is compensatory with respect to that of the PlaC acyltransferase. Hence, we made double mutants and found that lapA plaC mutants have an ~50-fold defect during infection of A. castellanii These data revealed, for the first time, the importance of LapA in any sort of infection; thus, we purified LapA and defined its crystal structure, activation by another T2S-dependent protease (ProA), and broad substrate specificity. When the amoebal infection medium was supplemented with amino acids, the defect of the lapA plaC mutant was reversed, implying that LapA generates amino acids for nutrition. Since the LapA and PlaC data did not fully explain the role of T2S in infection, we identified, via proteomic analysis, a novel secreted protein (NttD) that promotes infection of A. castellanii A lapA plaC nttD mutant displayed an even greater (100-fold) defect, demonstrating that the LapA, PlaC, and NttD data explain, to a significant degree, the importance of T2S. LapA-, PlaC-, and NttD-like proteins had distinct distribution patterns within and outside the Legionella genus. LapA was notable for having as its closest homologue an A. castellanii protein. IMPORTANCE Transmission of L. pneumophila to humans is facilitated by its ability to grow in Acanthamoeba species. We previously documented that type II secretion (T2S) promotes L. pneumophila infection of A. castellanii Utilizing transcriptional analysis and proteomics, double and triple mutants, and crystal structures, we defined three secreted substrates/effectors that largely clarify the role of T2S during infection of A. castellanii Particularly interesting are the unique functional overlap between an acyltransferase (PlaC) and aminopeptidase (LapA), the broad substrate specificity and eukaryotic-protein-like character of LapA, and the novelty of NttD. Linking LapA to amino acid acquisition, we defined, for the first time, the importance of secreted aminopeptidases in intracellular infection. Bioinformatic investigation, not previously applied to T2S, revealed that effectors originate from diverse sources and distribute within the Legionella genus in unique ways. The results of this study represent a major advance in understanding Legionella ecology and pathogenesis, bacterial secretion, and the evolution of intracellular parasitism.


    Organizational Affiliation

    Department of Microbiology and Immunology, Northwestern University Medical School, Chicago, Illinois, USA j.garnett@qmul.ac.uk n-cianciotto@northwestern.edu.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
Bacterial leucyl aminopeptidaseA, B393Legionella pneumophilaMutation(s): 0 
Gene Names: ERS253249_01626lpymg_03046
EC: 3.4.11.10
UniProt
Find proteins for Q5ZRR6 (Legionella pneumophila subsp. pneumophila (strain Philadelphia 1 / ATCC 33152 / DSM 7513))
Explore Q5ZRR6 
Go to UniProtKB:  Q5ZRR6
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupQ5ZRR6
Protein Feature View
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  • Reference Sequence
Small Molecules
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.87 Å
  • R-Value Free: 0.238 
  • R-Value Work: 0.192 
  • R-Value Observed: 0.195 
  • Space Group: P 21 21 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 76.597α = 90
b = 99.556β = 90
c = 104.012γ = 90
Software Package:
Software NamePurpose
REFMACrefinement
Aimlessdata reduction
SCALAdata scaling
PHASERphasing

Structure Validation

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Entry History & Funding Information

Deposition Data


Funding OrganizationLocationGrant Number
Medical Research Council (United Kingdom)United KingdomMR/M009920/10

Revision History  (Full details and data files)

  • Version 1.0: 2018-04-04
    Type: Initial release
  • Version 1.1: 2018-05-02
    Changes: Data collection, Database references