1. Structural Biology and Molecular Biophysics
Download icon

Insights into the ubiquitin transfer cascade catalyzed by the Legionella effector SidC

  1. David Jon Wasilko
  2. Qingqiu Huang
  3. Yuxin Mao  Is a corresponding author
  1. Cornell University, United States
Research Article
  • Cited 7
  • Views 1,036
  • Annotations
Cite this article as: eLife 2018;7:e36154 doi: 10.7554/eLife.36154

Abstract

The causative agent of Legionnaires' disease, Legionella pneumophila, delivers more than 330 virulent effectors to its host to establish an intracellular membrane-bound organelle called the Legionella containing vacuole. Among the army of Legionella effectors, SidC and its paralog SdcA have been identified as novel bacterial ubiquitin (Ub) E3 ligases. To gain insight into the molecular mechanism of SidC/SdcA as Ub ligases, we determined the crystal structures of a binary complex of the N-terminal catalytic SNL domain of SdcA with its cognate E2 UbcH5C and a ternary complex consisting of the SNL domain of SidC with the Ub-linked E2 UbcH7. These two structures reveal the molecular determinants governing the Ub transfer cascade catalyzed by SidC. Together, our data support a common mechanism in the Ub transfer cascade in which the donor Ub is immobilized with its C-terminal tail locked in an extended conformation, priming the donor Ub for catalysis.

Data availability

Atomic coordinates and structure factors for the reported structures have been deposited into the Protein Data Bank under the accession codes 6CP0 (SdcA-UbcH5C), 6CP2 (SidC-UbcH7~Ub)

The following data sets were generated
    1. Wasilko DJ
    2. Huang Q
    3. Mao Y
    (2018) structure for SdcA-UbcH5C
    Publicly available at the RCSB Protein Data Bank (accession no. 6CP0).
    1. Wasilko DJ
    2. Huang Q
    3. Mao Y
    (2018) structure for SidC-UbcH7~Ub
    Publicly available at the RCSB Protein Data Bank (accession no. 6CP2).

Article and author information

Author details

  1. David Jon Wasilko

    Department of Molecular Biology and Genetics, Cornell University, Ithaca, United States
    Competing interests
    The authors declare that no competing interests exist.
  2. Qingqiu Huang

    MacCHESS, Cornell University, Ithaca, United States
    Competing interests
    The authors declare that no competing interests exist.
  3. Yuxin Mao

    Molecualr Biology and Genetics/Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, United States
    For correspondence
    ym253@cornell.edu
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0002-5064-1397

Funding

National Institute of General Medical Sciences (5R01GM116964)

  • Yuxin Mao

The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.

Reviewing Editor

  1. Cynthia Wolberger, Johns Hopkins University, United States

Publication history

  1. Received: February 23, 2018
  2. Accepted: July 16, 2018
  3. Accepted Manuscript published: July 17, 2018 (version 1)
  4. Version of Record published: July 27, 2018 (version 2)

Copyright

© 2018, Wasilko et al.

This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.

Metrics

  • 1,036
    Page views
  • 196
    Downloads
  • 7
    Citations

Article citation count generated by polling the highest count across the following sources: Crossref, PubMed Central, Scopus.

Download links

A two-part list of links to download the article, or parts of the article, in various formats.

Downloads (link to download the article as PDF)

Download citations (links to download the citations from this article in formats compatible with various reference manager tools)

Open citations (links to open the citations from this article in various online reference manager services)

Further reading

    1. Structural Biology and Molecular Biophysics
    Yanyan Liu et al.
    Research Article

    Plexins are semaphorin receptors that play essential roles in mammalian neuronal axon guidance and in many other important mammalian biological processes. Plexin signaling depends on a semaphorin-induced dimerization mechanism, and is modulated by small GTPases of the Rho family, of which RND1 serves as a plexin activator yet its close homolog RhoD an inhibitor. Using molecular dynamics (MD) simulations we showed that RND1 reinforces the plexin dimerization interface whereas RhoD destabilizes it due to their differential interaction with the cell membrane. Upon binding plexin at the Rho-GTPase binding domain (RBD), RND1 and RhoD interact differently with the inner leaflet of the cell membrane, and exert opposite effects on the dimerization interface via an allosteric network involving the RBD, RBD linkers, and a buttress segment adjacent to the dimerization interface. The differential membrane interaction is attributed to the fact that, unlike RND1, RhoD features a short C-terminal tail and a positively charged membrane interface.

    1. Microbiology and Infectious Disease
    2. Structural Biology and Molecular Biophysics
    Kanika Khanna et al.
    Research Article Updated

    The Gram-positive bacterium Bacillus subtilis can divide via two modes. During vegetative growth, the division septum is formed at the midcell to produce two equal daughter cells. However, during sporulation, the division septum is formed closer to one pole to yield a smaller forespore and a larger mother cell. Using cryo-electron tomography, genetics and fluorescence microscopy, we found that the organization of the division machinery is different in the two septa. While FtsAZ filaments, the major orchestrators of bacterial cell division, are present uniformly around the leading edge of the invaginating vegetative septa, they are only present on the mother cell side of the invaginating sporulation septa. We provide evidence suggesting that the different distribution and number of FtsAZ filaments impact septal thickness, causing vegetative septa to be thicker than sporulation septa already during constriction. Finally, we show that a sporulation-specific protein, SpoIIE, regulates asymmetric divisome localization and septal thickness during sporulation.