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bioRxiv · 10.1101/2023.11.26.568766

Phytopathogenic cyclic glucohexadecaose from an inverting transglycosylase

Motouchi, S.·Komba, S.·Nakai, H.·Nakajima, M.
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Abstract

Xanthomonas species contain numerous notoriously well-known plant pathogens. Among various pathogenic factors, the role of -1,6-cyclized {beta}-1,2-glucohexadecaose (C{beta}G16) produced by Xanthomonas campestris pv. campestris was shown previously to be vital for infecting model organisms Arabidopsis thaliana and Nicotiana benthamiana. However, enzymes responsible for biosynthesising C{beta}G16 are essentially unknown, which limits the generation of agrichemicals that inhibit C{beta}G16 synthesis. In this study, we discovered that OpgD from X. campestris pv. campestris converts linear {beta}-1,2-glucan to C{beta}G16. Structural and functional analyses revealed that OpgD from X. campestris pv. campestris possesses an anomer-inverting transglycosylation mechanism, which is unprecedented among carbohydrate-active enzymes. The discovery of this unprecedented glucan-generating mechanism reveals a new foundation for the enzymatic synthesis of carbohydrates. Furthermore, identifying C{beta}G16 synthase highly conserved in Xanthomonas provides a broadly adaptable drug target for new-genre agrichemicals that overcome antimicrobial-resistant bacterial issues.

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Motouchi, S., Komba, S., Nakai, H., Nakajima, M.. 2023-11-27. Phytopathogenic cyclic glucohexadecaose from an inverting transglycosylase. https://doi.org/10.1101/2023.11.26.568766

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