Molecular Basis for the Adaptive Evolution of Environment Sensing by H-NS Proteins

Zhao, X.; Kharchenko, V.; Shahul Hameed, U. F.; Liao, C.; Huser, F.; Remington, J. M.; Radhakrishnan, A.; Jaremko, M.; Jaremko, Łukasz; Arold, S. T.; Li, J.

doi:10.1101/2020.04.21.053520

bioRxiv · 10.1101/2020.04.21.053520

Molecular Basis for the Adaptive Evolution of Environment Sensing by H-NS Proteins

Zhao, X.·Kharchenko, V.·Shahul Hameed, U. F.·Liao, C.·Huser, F.·Remington, J. M.·Radhakrishnan, A.·Jaremko, M.·Jaremko, Łukasz·Arold, S. T.·Li, J.

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Abstract

The DNA-binding protein H-NS is a pleiotropic gene regulator in gram-negative bacteria. Through its capacity to sense temperature and other environmental factors, H-NS allows pathogens like Salmonella to adapt their gene expression, and hence toxicity and biological responses, to their presence inside or outside warm-blooded hosts. To investigate how this sensing mechanism may have evolved to fit different bacterial lifestyles, we compared H-NS orthologs from bacteria that infect humans, plants, and insects, and from bacteria that live on a deep-sea hypothermal vent. The combination of biophysical characterization, high-resolution proton-less NMR spectroscopy and molecular simulations revealed, at an atomistic level, how the same general mechanism was adapted to specific habitats and lifestyles. In particular, we demonstrate how environment-sensing characteristics arise from specifically positioned intra- or intermolecular electrostatic interactions. Our integrative approach clarified the mechanism for H-NS-mediated environmental sensing and suggests that it resulted from the exaptation of an ancestral protein feature.

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Zhao, X., Kharchenko, V., Shahul Hameed, U. F., Liao, C., Huser, F., Remington, J. M., Radhakrishnan, A., Jaremko, M., Jaremko, Łukasz, Arold, S. T., Li, J.. 2020-04-24. Molecular Basis for the Adaptive Evolution of Environment Sensing by H-NS Proteins. https://doi.org/10.1101/2020.04.21.053520

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