A MUTANT FORM OF THE RIBOSOMAL-PROTEIN L1 REVEALS CONFORMATIONAL FLEXIBILITY

The crystal structure of the mutant S179C of the ribosomal protein L1 from Thermus thermophilus has been determined at 1.9 Angstrom resoluti on. The mutant molecule displays a small but significant opening of th e cavity between the two domains, The domain movement seems to be faci litated by the flexibility of at least two conserved glycines, These g lycines may be necessary for the larger conformational change needed f or an induced fit mechanism upon binding RNA, The domain movement make s a disulfide bridge possible between the incorporated cysteines in tw o monomers of the mutant L1. (C) 1997 Federation of European Biochemic al Societies.