6x0b

Publication Abstract from PubMed

Thioredoxins are regulatory proteins that reduce disulfide bonds on target proteins. NaTrxh, which belongs to the plant thioredoxin family h subgroup 2, interacts and reduces the S-RNase enhancing its ribonuclease activity seven-fold, resulting an essential protein for pollen rejection inNicotiana.Here, the crystal structure of NaTrxh at 1.7 A by X-ray diffraction is reported. NaTrxh conserves the typical fold observed in other thioredoxins from prokaryotes and eukaryotes, but it contains extensions towards both N- and C-termini.The NaTrxh N-terminal extension participates in the reduction of S-RNase, and in the structure reported here, this is orientated towards the reactive site. The interaction between SF11-RNase and the NaTrxh N-terminal was simulated and the short-lived complex observed lasted for a tenth of ns. Moreover, we identified certain amino acids as SF11-RNase-E155 and NaTrxh-M104 as good candidates to contribute to the stability of the complex. Furthermore, we simulated the reduction of the C153-C186 SF11-RNase disulfide bond and observed subtle changes that affect the entire core, which might explain the increase in the ribonuclease activity of S-RNase when it is reduced by NaTrxh.

High resolution crystal structure of NaTrxh from Nicotiana alata and its interaction with the S-RNase.,Maria Daniela TR, Lilian GS, Rogelio RS, Javier Andres JD, Yuridia CZ, Felipe CG J Struct Biol. 2020 Jul 16:107578. doi: 10.1016/j.jsb.2020.107578. PMID:32682729^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.