The NMR structure of the engineered halophilic DnaE intein for segmental isotopic labeling using conditional protein splicing.

Autor: Heikkinen HA; Institute of Biotechnology, University of Helsinki, PO Box 65, Helsinki, FIN-00014, Finland., Aranko AS; Institute of Biotechnology, University of Helsinki, PO Box 65, Helsinki, FIN-00014, Finland. Electronic address: sesilja.aranko@aalto.fi., Iwaï H; Institute of Biotechnology, University of Helsinki, PO Box 65, Helsinki, FIN-00014, Finland. Electronic address: hideo.iwai@helsinki.fi.
Jazyk: angličtina
Zdroj: Journal of magnetic resonance (San Diego, Calif. : 1997) [J Magn Reson] 2022 May; Vol. 338, pp. 107195. Date of Electronic Publication: 2022 Mar 18.
DOI: 10.1016/j.jmr.2022.107195
Abstrakt: Protein trans-splicing catalyzed by split inteins has been used for segmental isotopic labeling of proteins for alleviating the complexity of NMR signals. Whereas inteins spontaneously trigger protein splicing upon protein folding, inteins from extremely halophilic organisms require a high salinity condition to induce protein splicing. We designed and created a salt-inducible intein from the widely used DnaE intein from Nostoc punctiforme by introducing 29 mutations, which required a lower salt concentration than naturally occurring halo-obligate inteins. We determined the NMR solution structure of the engineered salt-inducible DnaE intein in 2 M NaCl, showing the essentially identical three-dimensional structure to the original one, albeit it unfolds without salts. The NMR structure of a halo-obligate intein under high salinity suggests that the stabilization of the active folded conformation is not a mere result of various intramolecular interactions but the subtle energy balance from the complex interactions, including the solvation energy, which involve waters, ions, co-solutes, and protein polypeptide chains.
Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
(Copyright © 2022 The Authors. Published by Elsevier Inc. All rights reserved.)
Databáze: MEDLINE
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