Protease mimicry: Dissecting the ester bond crosslinking mechanics in bacterial adhesin proteins
The ester bond crosslink discovered within bacterial adhesin proteins offers a captivating insight into the convergent evolution of enzyme-like machinery. Crystal structures reveal a putative catalytic triad comprising an acid-base-nucleophile combination and an oxyanion-like site that suggests a serine protease-like mechanism drives the crosslinking process. We now provide confirmation of the mechanism, revealing functional catalytic dyads or triads, and the recapitulation of protease machinery from a Pseudomonas bacterium and a human cytomegalovirus related only by convergent evolution. Molecular dynamics simulations suggest how a conservative threonine-to-serine mutation of the nucleophile induces hydrolysis and eliminates the ester bond crosslink. Collectively, our structural, functional, and computational efforts detail the molecular intricacies of intramolecular ester bond formation and underscore the convergent evolutionary adaptations of bacteria in exploiting enzyme-like machinery to protect essential adhesin proteins from the mechanical, biological, and chemical hostilities of their replicative niche.
Authors
- Vanessa Ung (ORCID: https://orcid.org/0000-0002-9494-2837)
- Paul G. Young (ORCID: https://orcid.org/0000-0002-7325-1869)
- Davide Mercadante (ORCID: https://orcid.org/0000-0001-6792-7706)
- Pavan K. Shetty (ORCID: https://orcid.org/0000-0002-6484-7417)
- Ivanhoe K. H. Leung (ORCID: https://orcid.org/0000-0003-0633-6771)
- J.R. Keown (ORCID: https://orcid.org/0000-0003-0159-9257)
- Xinlu Liu (ORCID: https://orcid.org/0000-0003-4324-2504)
- Edward N. Baker (ORCID: https://orcid.org/0000-0003-2456-7661)
- C.J. Squire (ORCID: https://orcid.org/0000-0001-9212-0461)
- Y. Yosaatmadja (ORCID: https://orcid.org/0000-0003-2875-5993)
- David C. Goldstone (ORCID: https://orcid.org/0000-0003-0069-9408)
- Julia K. Wardega (ORCID: https://orcid.org/0000-0003-1084-3944)
- Yixuan Zhao (ORCID: https://orcid.org/0009-0004-3124-1365)
- Sophie Schoensee
Institutions
- University of Auckland (NZ)
- The University of Melbourne (AU)
- University of Warwick (GB)
- Maurice Wilkins Centre (NZ)
Publication Details
- Journal
- Protein Science
- Published
- 2025-07-26
- DOI
- https://doi.org/10.1002/pro.70238
- Primary Topic
- Biochemical and Structural Characterization
- Type
- article
- Field-Weighted Citation Impact
- 0.00
Funders
- Australian Nuclear Science and Technology Organisation
- Australian Cancer Research Foundation
- Australian Synchrotron
- University of Auckland
- Marsden Fund