Crystal structure of PfRh5, an essential P. falciparum ligand for invasion of human erythrocytes

  1. Lin Chen
  2. Yibin Xu
  3. Julie Healer
  4. Jenny K Thompson
  5. Brian J Smith
  6. Michael C Lawrence
  7. Alan F Cowman  Is a corresponding author
  1. Walter and Eliza Hall Institute of Medical Research, Australia
  2. La Trobe University, Australia

Abstract

Plasmodium falciparum causes the most severe form of malaria in humans and is responsible for over 700,000 deaths annually. It is an obligate intracellular parasite and invades erythrocytes where it grows in a relatively protected niche. Invasion of erythrocytes is essential for parasite survival and this involves interplay of multiple protein-protein interactions. One of the most important interactions is binding of parasite invasion ligand families EBLs and PfRhs to host receptors on the surface of erythrocytes. PfRh5 is the only essential invasion ligand within the PfRh family and is an important vaccine candidate. PfRh5 binds the host receptor basigin. Here we have determined the crystal structure of PfRh5 using diffraction data to 2.18 Å resolution. PfRh5 exhibits a novel fold comprising nine mostly-anti-parallel α-helices encasing a N-terminal β-hairpin, with the overall shape being an elliptical disk. This is the first three-dimensional structure determined for the PfRh family of proteins.

Article and author information

Author details

  1. Lin Chen

    Walter and Eliza Hall Institute of Medical Research, Melbourne, Australia
    Competing interests
    The authors declare that no competing interests exist.
  2. Yibin Xu

    Walter and Eliza Hall Institute of Medical Research, Melbourne, Australia
    Competing interests
    The authors declare that no competing interests exist.
  3. Julie Healer

    Walter and Eliza Hall Institute of Medical Research, Melbourne, Australia
    Competing interests
    The authors declare that no competing interests exist.
  4. Jenny K Thompson

    Walter and Eliza Hall Institute of Medical Research, Melbourne, Australia
    Competing interests
    The authors declare that no competing interests exist.
  5. Brian J Smith

    La Trobe University, Melbourne, Australia
    Competing interests
    The authors declare that no competing interests exist.
  6. Michael C Lawrence

    Walter and Eliza Hall Institute of Medical Research, Melbourne, Australia
    Competing interests
    The authors declare that no competing interests exist.
  7. Alan F Cowman

    Walter and Eliza Hall Institute of Medical Research, Melbourne, Australia
    For correspondence
    cowman@wehi.edu.au
    Competing interests
    The authors declare that no competing interests exist.

Reviewing Editor

  1. Axel Brakhage, Leibniz Institute for Natural Product Research and Infection Biology - Hans Knöll Institute, Germany

Publication history

  1. Received: July 29, 2014
  2. Accepted: October 7, 2014
  3. Accepted Manuscript published: October 8, 2014 (version 1)
  4. Version of Record published: November 3, 2014 (version 2)

Copyright

© 2014, Chen 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

  • 3,176
    Page views
  • 374
    Downloads
  • 48
    Citations

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

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)

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

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

  1. Lin Chen
  2. Yibin Xu
  3. Julie Healer
  4. Jenny K Thompson
  5. Brian J Smith
  6. Michael C Lawrence
  7. Alan F Cowman
(2014)
Crystal structure of PfRh5, an essential P. falciparum ligand for invasion of human erythrocytes
eLife 3:e04187.
https://doi.org/10.7554/eLife.04187

Further reading

    1. Structural Biology and Molecular Biophysics
    Nicola Galvanetto, Zhongjie Ye ... Vincent Torre
    Research Article Updated

    Single-molecule force spectroscopy (SMFS) uses the cantilever tip of an atomic force microscopy (AFM) to apply a force able to unfold a single protein. The obtained force-distance curve encodes the unfolding pathway, and from its analysis it is possible to characterize the folded domains. SMFS has been mostly used to study the unfolding of purified proteins, in solution or reconstituted in a lipid bilayer. Here, we describe a pipeline for analyzing membrane proteins based on SMFS, which involves the isolation of the plasma membrane of single cells and the harvesting of force-distance curves directly from it. We characterized and identified the embedded membrane proteins combining, within a Bayesian framework, the information of the shape of the obtained curves, with the information from mass spectrometry and proteomic databases. The pipeline was tested with purified/reconstituted proteins and applied to five cell types where we classified the unfolding of their most abundant membrane proteins. We validated our pipeline by overexpressing four constructs, and this allowed us to gather structural insights of the identified proteins, revealing variable elements in the loop regions. Our results set the basis for the investigation of the unfolding of membrane proteins in situ, and for performing proteomics from a membrane fragment.

    1. Biochemistry and Chemical Biology
    2. Structural Biology and Molecular Biophysics
    Hemant N Goswami, Jay Rai ... Hong Li
    Research Article

    Cas7-11 is a Type III-E CRISPR Cas effector that confers programmable RNA cleavage and has potential applications in RNA interference. Cas7-11 encodes a single polypeptide containing four Cas7- and one Cas11-like segments that obscures the distinction between the multi-subunit Class 1 and the single-subunit Class-2 CRISPR-Cas systems. We report a cryo-EM structure of the active Cas7-11 from Desulfonema ishimotonii (DiCas7-11) that reveals the molecular basis for RNA processing and interference activities. DiCas7-11 arranges its Cas7- and Cas11-like domains in an extended form that resembles the backbone made up by four Cas7 and one Cas11 subunits in the multi-subunit enzymes. Unlike the multi-subunit enzymes, however, the backbone of DiCas7-11 contains evolutionarily different Cas7 and Cas11 domains, giving rise to their unique functionality. The first Cas7-like domain nearly engulfs the last 15 direct repeat nucleotides in processing and recognition of the CRISPR RNA, and its free-standing fragment retains most of the activity. Both the second and the third Cas7-like domains mediate target RNA cleavage in a metal-dependent manner. The structure and mutational data indicate that the long variable insertion to the fourth Cas7 domain has little impact to RNA processing or targeting, suggesting the possibility for engineering a compact and programmable RNA interference tool.