The interaction of SsoHflX with the 50S ribosomal subunit (rib. s.u.) results in the broadening of the SsoHflX resonances. (A) Overlays of the 1H one-dimensional spectra of SsoHflX in the presence of GTP (upper panel, black line), the S. solfataricus 50S ribosomal subunit (lower panel, black line), and SsoHflX plus the 50S ribosomal subunit in the presence of GTP (both panels, red line). (B) 1H projection of the 1H-15N SOFAST-HMQC of SsoHflX plus 50S ribosomal subunit in the presence of GTP at 50°C. The entire spectrum of SsoHflX is broadened beyond detection.