GroES co-chaperonin small-angle X-ray scattering study shows ring orifice increase in solution

CroES consists of seven identical 10 kDa subunits and is involved in assist ing protein folding as the partner of another oligomeric protein, the GroEL chaperonin. Wore we studied the GroES structure in solution using small-an gle X-ray scattering (SAXS), The SASS pattern, calculated for the CroES cry stal structure, was found to be different from the experimental one measure d in solution. The synchronic shift in the radial direction and some turnin g of the protein subunits eliminate the difference and result in the incase of the hole diameter in the GroES ring-like structure from 8 Angstrom in t he crystal to 21 Angstrom in solution. (C) 2000 Federation of European Bioc hemical Societies.