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bioRxiv · 10.1101/2019.12.19.882373

smFRET Detects Dual Binding Modes Modulated by Proline Isomerization in a Mega-Dalton Multi-Enzyme Complex

Vera, A. M.·Galera-Prat, A.·Wojciechowski, M.·Rozycki, B.·Laurents, D. V.·Carrion-Vazquez, M.·Cieplak, M.·Tinnefeld, P.
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Abstract

Cellulose is the most abundant organic molecule on Earth and represents a renewable and practically everlasting feedstock for the production of biofuels and chemicals. Self-assembled owing to the high-affinity cohesin-dockerin interaction, cellulosomes are huge multi-enzyme complexes with unmatched efficiency in the degradation of recalcitrant lignocellulosic substrates. The recruitment of diverse dockerin-borne enzymes into a multicohesin protein scaffold dictates the three-dimensional layout of the complex, and interestingly two alternative binding modes have been proposed. Using single-molecule Fluorescence Resonance Energy Transfer, molecular dynamics simulations and NMR measurements on a range of cohesin-dockerin pairs, we directly detect varying distributions between these binding modes that follow a built-in cohesin-dockerin code. Surprisingly, we uncover a prolyl isomerase-modulated allosteric control mechanism, mediated by the isomerization state of a single proline residue, which regulates the distribution and kinetics of binding modes. Overall, our data provide a novel mechanistic understanding of the structural plasticity and dynamics of cellulosomes.Competing Interest StatementThe authors have declared no competing interest.View Full Text

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Vera, A. M., Galera-Prat, A., Wojciechowski, M., Rozycki, B., Laurents, D. V., Carrion-Vazquez, M., Cieplak, M., Tinnefeld, P.. 2019-12-19. smFRET Detects Dual Binding Modes Modulated by Proline Isomerization in a Mega-Dalton Multi-Enzyme Complex. https://doi.org/10.1101/2019.12.19.882373

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