Backbone and methyl resonances assignment of the 87 kDa prefoldin from Pyrococcus horikoshii

Prefoldin is a heterohexameric protein assembly which acts as a co-chaperonin for the well conserved Hsp60 chaperonin, present in archaebacteria and the eukaryotic cell cytosol. Prefoldin is a holdase, capturing client proteins and subsequently transferring them to the Hsp60 chamber for refolding. The chaperonin family is implicated in the early stages of protein folding and plays an important role in proteostasis in the cytosol. Here, we report the assignment of H-1(N), N-15, C-13 ', C-13(alpha), C-13(beta), H-1(methyl), and C-13(methyl) chemical shifts of the 87 kDa prefoldin from the hyperthermophilic archaeon Pyrococcus horikoshii, consisting of two alpha and four beta subunits. 100% of the [C-13, H-1]-resonances of A(beta), I-delta 1, I-delta 2, T-gamma 2, V-gamma 2 methyl groups were successfully assigned for both subunits. For the beta subunit, showing partial peak doubling, 80% of the backbone resonances were assigned. In the alpha subunit, large stretches of backbone resonances were not detectable due to slow (mu s-ms) time scale dynamics. This conformational exchange limited the backbone sequential assignment of the alpha subunit to 57% of residues, which corresponds to 84% of visible NMR signals.

Automated summary

Prefoldin acts as a co-chaperonin for Hsp60 in protein folding, with successful assignment of chemical shifts for the prefoldin from Pyrococcus horikoshii. The protein assembly captures and transfers client proteins for refolding, playing a key role in proteostasis.