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bioRxiv · 10.1101/2024.11.21.623966

Structural diversity and oligomerization of bacterial ubiquitin-like proteins

Gong, M.·Ye, Q.·Gu, Y.·Chambers, L. R.·Bobkov, A. A.·Arakawa, N. K.·Matyszewski, M.·Corbett, K. D.
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Abstract

Bacteria possess a variety of operons with homology to eukaryotic ubiquitination pathways that encode predicted E1, E2, E3, deubiquitinase, and ubiquitin-like proteins. Some of these pathways have recently been shown to function in anti-bacteriophage immunity, but the biological functions of others remain unknown. Here, we show that ubiquitin-like proteins in two bacterial operon families show surprising architectural diversity, possessing one to three {beta}-grasp domains preceded by diverse N-terminal domains. We find that a large group of bacterial ubiquitin-like proteins possess three {beta}-grasp domains and form homodimers and helical filaments mediated by conserved Ca2+ ion binding sites. Our findings highlight a distinctive mode of self-assembly for ubiquitin-like proteins, and suggest that Ca2+-mediated ubiquitin-like protein filament assembly and/or disassembly enables cells to sense and respond to stress conditions that alter intracellular metal ion concentration.

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Gong, M., Ye, Q., Gu, Y., Chambers, L. R., Bobkov, A. A., Arakawa, N. K., Matyszewski, M., Corbett, K. D.. 2024-11-21. Structural diversity and oligomerization of bacterial ubiquitin-like proteins. https://doi.org/10.1101/2024.11.21.623966

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