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bioRxiv · 10.1101/2022.01.04.474796

Structure-function-dynamics relationships in the peculiar Planktothrix PCC7805 OCP1: impact of his-tagging and carotenoid type.

Wilson, A.·Andreeva, E. A.·Nizinski, S.·Talbot, L.·Hartmann, E.·Schlichting, I.·Burdzinski, G.·Sliwa, M.·KIRILOVSKY, D.·Colletier, J.-P.
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Abstract

The orange carotenoid protein (OCP) is a photoactive protein involved in cyanobacterial photoprotection. Here, we report on the functional, spectral and structural characteristics of the peculiar Planktothrix PCC7805 OCP (Plankto-OCP). We show that this OCP variant is characterized by higher photoactivation and recovery rates, and a stronger energy-quenching activity, compared to other OCP studied thus far. We characterize the effect of the functionalizing carotenoid and of his-tagging on these reactions, and identify the time scales on which these modifications affect photoactivation. The presence of a his-tag at the C-terminus has a large influence on photoactivation, thermal recovery and PBS-fluorescence quenching, and likewise for the nature of the carotenoid that additionally affects the yield and characteristics of excited states and the ns-s dynamics of photoactivated OCP. By solving the structures of Plankto-OCP in the ECN- and CAN-functionalized states, each in two closely-related crystal forms, we further unveil the molecular breathing motions that animate Plankto-OCP at the monomer and dimer levels. We finally discuss the structural changes that could explain the peculiar properties of Plankto-OCP. HighlightsO_LIComplete functional characterization of Synechocystis and Planktothrix OCP C_LIO_LIHitherto unknown structures of ECN- and CAN-functionalized Planktothrix OCP C_LIO_LIInsights into fs-s timescale photodynamics of ECN- and CAN-functionalized Synechocystis and Planktothrix OCP C_LI

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Wilson, A., Andreeva, E. A., Nizinski, S., Talbot, L., Hartmann, E., Schlichting, I., Burdzinski, G., Sliwa, M., KIRILOVSKY, D., Colletier, J.-P.. 2022-01-04. Structure-function-dynamics relationships in the peculiar Planktothrix PCC7805 OCP1: impact of his-tagging and carotenoid type.. https://doi.org/10.1101/2022.01.04.474796

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