Three-dimensional solution structure, dynamics and binding of thioredoxin m from Pisum sativum Neira, José Luis Palomino Schätzlein, Martina Rejas, Virginia Traverso Gutiérrez, José Ángel Rico, Manual López Gorgé, Julio Chueca, Ana Cámara-Artigas, Ana Thioredoxin Protein-protein interactions NMR Thioredoxins (TRXs) are ubiquitous small, globular proteins involved in cell redox processes. In this work, we report the solution structure of TRX m from Pisum sativum (pea), which has been determined on the basis of 1444 nuclear Overhauser effect- (NOE-) derived distance constraints. The average pairwise root-mean-square deviation (RMSD) for the 20 best structures for the backbone residues (Val7-Glu102) was 1.42 ± 0.15 Å, and 1.97 ± 0.15 Å when all heavy atoms were considered. The structure corresponds to the typical fold of TRXs, with a central five-stranded β-sheet flanked by four α-helices. Some residues had an important exchange dynamic contribution: those around the active site; at the C terminus of β-strand 3; and in the loop preceding α-helix 4. Smaller NOE values were observed at the N and C-terminal residues forming the elements of the secondary structure or, alternatively, in the residues belonging to the loops between those elements. A peptide derived from pea fructose-1,6-biphosphatase (FBPase), comprising the preceding region to the regulatory sequence of FBPase (residues Glu152 to Gln179), was bound to TRX m with an affinity in the low micromolar range, as measured by fluorescence and NMR titration experiments. Upon peptide addition, the intensities of the cross-peaks of all the residues of TRX m were affected, as shown by NMR. The value of the dissociation constant of the peptide from TRX m was larger than that of the intact FBPase, indicating that there are additional factors in other regions of the polypeptide chain of the latter protein affecting the binding to thioredoxin. 2024-05-28T07:13:50Z 2024-05-28T07:13:50Z 2024-02-01 journal article Neira, José L., et al. Three-dimensional solution structure, dynamics and binding of thioredoxin m from Pisum sativum. International Journal of Biological Macromolecules 262 (2024) 129781 [10.1016/j.ijbiomac.2024.129781] https://hdl.handle.net/10481/92132 10.1016/j.ijbiomac.2024.129781 eng http://creativecommons.org/licenses/by-nc-nd/4.0/ open access Attribution-NonCommercial-NoDerivatives 4.0 Internacional Elsevier