Ribosome biogenesis in eukaryotes is a complex and highly orchestrated process
involving more than 200 accessory factors in addition to ribosomal RNAs and
ribosomal proteins. Among the many factors involved, Sqt1p has been reported to
specifically bind to uL16 and to act as a chaperone. The crystal structure of
full-length Sqt1p from the yeast Saccharomyces cerevisiae has been solved at
3.35 Å resolution. A SAD experiment at the Se K edge and an S-SAD
experiment on the same selenomethionine-substituted protein crystal allowed
unambiguous positioning of the selenomethionine and Cys residues. On the basis
of the atomic structure of Sqt1p, the potential residues involved in uL16
interaction were identified and tested.
