Analysis of Ribosome Protected Fragments of mRNAs from yeast strains either expressing Rio1p or depleted of Rio1p

mRNAs bound by ribosomes from yeast cells were analysed in order to determine the exact position of ribosomes in the presence or absence of Rio1p. Beside total Ribosome Protected Fragments (RPFs), RPFs from mRNAs protected by immature pre-40S pre-ribosomes was also analysed. The analysis showed that immature 40S ribosomes can carry out translation and their premature entry into translation is hindered by Rio1p.