Structure of a bacterial 30S ribosomal subunit at 5.5 Å resolution
The 30S ribosomal subunit binds messenger RNA and the anticodon stem-loop of transfer RNA during protein synthesis. A crystallographic analysis of the structure of the subunit from the bacterium Thermus thermophilus is presented. At a resolution of 5.5 Å, the phosphate backbone of the ribosomal RNA is visible, as are the α-helices of the ribosomal proteins, enabling double-helical regions of RNA to be identified throughout the subunit, all seven of the small-subunit proteins of known crystal structure to be positioned in the electron density map, and the fold of the entire central domain of the small-subunit ribosomal RNA to be determined.
© 1999 Nature Publishing Group. Received 14 June; accepted 13 July 1999. This work was supported by grants from the US NIH (to S. W. White & V.R.), the UK MRC and the University of Utah. Beamlines X12B and X25 at the NSLS are supported by the Office of Basic Energy Research of the US Department of Energy and by the NIH. We thank L. Berman and H. Lewis for their help on beamline X25; T. Terwilliger for advice on using SOLVE; P. Reversi and C. Vonrhein for discussions on phasing strategies; M. Pope for gifts of compounds of polytungstate clusters; J. Löwe and G.Schneider for gifts of hexatantalum bromide; B. S. Brunschwig and M. H. Chou for synthesizing osmium hexammine chloride; and S. C. Harrison, K. Nagai and D. Rhodes for critical comments on the manuscript. Coordinates for our partial model fo the 30S have been deposited in the protein data bank, with accession number 1QD7.