Henrique dos Santos Rodrigues, F, Firczuk, H, Breeze, A orcid.org/0000-0001-9723-3350 et al. (5 more authors)
(2019)
The Leishmania PABP1–eIF4E4 interface: a novel 5′–3′ interaction architecture for trans-spliced mRNAs.
Nucleic Acids Research, 47 (3).
pp. 1493-1504.
ISSN 0305-1048
Abstract
Trans-splicing of trypanosomatid polycistronic transcripts produces polyadenylated monocistronic mRNAs modified to form the 5′ cap4 structure (m7Gpppm36,6,2′Apm2′Apm2′Cpm23,2′U). NMR and X-ray crystallography reveal that Leishmania has a unique type of N-terminally-extended cap-binding protein (eIF4E4) that binds via a PAM2 motif to PABP1. This relies on the interactions of a combination of polar and charged amino acid side-chains together with multiple hydrophobic interactions, and underpins a novel architecture in the Leishmania cap4-binding translation factor complex. Measurements using microscale thermophoresis, fluorescence anisotropy and surface plasmon resonance characterize the key interactions driving assembly of the Leishmania translation initiation complex. We demonstrate that this complex can accommodate Leishmania eIF4G3 which, unlike the standard eukaryotic initiation complex paradigm, binds tightly to eIF4E4, but not to PABP1. Thus, in Leishmania, the chain of interactions 5′cap4-eIF4E4–PABP1-poly(A) bridges the mRNA 5′ and 3′ ends. Exceptionally, therefore, by binding tightly to two protein ligands and to the mRNA 5′ cap4 structure, the trypanosomatid N-terminally extended form of eIF4E acts as the core molecular scaffold for the mRNA-cap-binding complex. Finally, the eIF4E4 N-terminal extension is an intrinsically disordered region that transitions to a partly folded form upon binding to PABP1, whereby this interaction is not modulated by poly(A) binding to PABP1
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © The Author(s) 2018. Published by Oxford University Press on behalf of Nucleic Acids Research. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted reuse, distribution, and reproduction in any medium, provided the original work is properly cited |
Dates: |
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Institution: | The University of Leeds |
Academic Units: | The University of Leeds > Faculty of Biological Sciences (Leeds) > School of Molecular and Cellular Biology (Leeds) > NMR (Leeds) The University of Leeds > Faculty of Engineering & Physical Sciences (Leeds) > School of Chemistry (Leeds) > Organic Chemistry (Leeds) |
Funding Information: | Funder Grant number MRC MR/N017447/1 |
Depositing User: | Symplectic Publications |
Date Deposited: | 22 Nov 2018 13:22 |
Last Modified: | 25 Jun 2023 21:36 |
Status: | Published |
Publisher: | Oxford University Press |
Identification Number: | 10.1093/nar/gky1187 |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:138924 |