7QIL

Solution NMR structure of halophilic DnaE intein

Summary for 7QIL

• Entry DOI: 10.2210/pdb7qil/pdb
• NMR Information: BMRB: 34695
• Descriptor: DnaE intein (1 entity in total)
• Functional Keywords: protein splicing, segmental isotopic labeling, conditional protein splicing, protein engineering, splicing
• Biological source: Nostoc
• Total number of polymer chains: 1
• Total formula weight: 15460.54

Authors

Heikkinen, H.A.,Aranko, S.A.,Iwai, H. (deposition date: 2021-12-15, release date: 2022-04-27, Last modification date: 2024-06-19)

Primary citation

Heikkinen, H.A.,Aranko, A.S.,Iwai, H.
The NMR structure of the engineered halophilic DnaE intein for segmental isotopic labeling using conditional protein splicing.
J.Magn.Reson., 338:107195-107195, 2022

PubMed Abstract: 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.

PubMed: 35398651
DOI: 10.1016/j.jmr.2022.107195

Experimental method

SOLUTION NMR