W. Kudlicki et al., RENATURATION OF RHODANESE BY TRANSLATIONAL ELONGATION-FACTOR (EF) TU - PROTEIN REFOLDING BY EF-TU FLEXING, The Journal of biological chemistry, 272(51), 1997, pp. 32206-32210
The translation elongation factor (EF) Tu has chaperone-like capacity
to promote renaturation of denatured rhodanese. This renaturation acti
vity is greatly increased under conditions in which the factor can osc
illate between the open and closed conformations that are induced by G
DP and GTP, respectively, Oscillation occurs during GTP hydrolysis and
subsequent replacement of GDP by EF-Ts which is then displaced by GTP
, Renaturation of rhodanese and GTP hydrolysis by EF-Tu are greatly en
hanced by the guanine nucleotide exchange factor EF-Ts, However, renat
uration is reduced under conditions that stabilize EF-Tu in either the
open or closed conformation, Both GDP and the nonhydrolyzable analog
of GTP, GMP-PCP, inhibit renaturation. Kirromycin and pulvomycin, anti
biotics that specifically bind to EF-Tu and inhibit its activity in pe
ptide elongation, also strongly inhibit EF-Tu-mediated renaturation of
denatured rhodanese to levels near those observed for spontaneous, un
assisted refolding, Kirromycin locks EF-Tu in the open conformation in
the presence of either GTP or GDP, whereas pulvomycin locks the facto
r in the closed conformation, The results lead to the conclusion that
flexing of EF-Tu, especially as occurs between its open and closed con
formations, is a major factor in its chaperone-like refolding activity
.