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Structural and functional insights into oligopeptide acquisition by the RagAB transporter from Porphyromonas gingivalis

Lookup NU author(s): Mariusz Madej, Dr Arnaud Basle, Professor Bert van den Berg



This is the authors' accepted manuscript of an article that has been published in its final definitive form by Nature Publishing Group, 2020.

For re-use rights please refer to the publisher's terms and conditions.


Porphyromonas gingivalis, an asaccharolytic member of the Bacteroidetes, is a keystone pathogen in human periodontitis that may also contribute to the development of other chronic inflammatory diseases. P. gingivalis utilizes protease-generated peptides derived from extracellular proteins for growth, but how those peptides enter the cell is not clear. Here we identify RagAB as the outer membrane importer for peptides. X-ray crystal structures show that the transporter forms a dimeric RagA2B2 complex, with the RagB substrate-binding surface-anchored lipoprotein forming a closed lid on the RagA TonB-dependent transporter. Cryo-electron microscopy structures reveal the opening of the RagB lid and thus provide direct evidence for a "pedal bin" nutrient uptake mechanism. Together with mutagenesis, peptide binding studies and RagAB peptidomics, our work identifies RagAB as a dynamic, selective OM oligopeptide acquisition machine that is essential for the efficient utilisation of proteinaceous nutrients by P. gingivalis.

Publication metadata

Author(s): Madej M, White JBR, Nowakowska Z, Rawson S, Scavenius C, Enghild JJ, Bereta GP, Pothula K, Kleinekathoefer U, Baslé A, Ranson NA, Potempa J, van den Berg B

Publication type: Article

Publication status: Published

Journal: Nature Microbiology

Year: 2020

Volume: 5

Pages: 1016-1025

Print publication date: 01/08/2020

Online publication date: 11/05/2020

Acceptance date: 31/03/2020

Date deposited: 13/06/2020

ISSN (electronic): 2058-5276

Publisher: Nature Publishing Group


DOI: 10.1038/s41564-020-0716-y

PubMed id: 32393857


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