YbeY is required for ribosome small subunit assembly and tRNA processing in human mitochondria

Mitochondria contain their own translation apparatus which enables them to produce the polypeptides encoded in their genome. The mitochondrially-encoded RNA components of the mitochondrial ribosome require various post-transcriptional processing steps. Additional protein factors are required to facilitate the biogenesis of the functional mitoribosome. We have characterised a mitochondrially-localized protein, YbeY, which interacts with the assembling mitoribosome through the small subunit. Loss of YbeY leads to a severe reduction in mitochondrial translation and a loss of cell viability, caused by less accurate mitochondrial mt-tRNASer(AGY) processing from the primary transcript and an accumulation of immature mitochondrial small subunit. Our results suggest that YbeY performs a dual function in mitochondria coupling tRNA processing to mitoribosome biogenesis. Issue SectionNucleic Acid Enzymes O_FIG O_LINKSMALLFIG WIDTH=194 HEIGHT=200 SRC="FIGDIR/small/874305v1_ufig1.gif" ALT="Figure 1"> View larger version (34K): org.highwire.dtl.DTLVardef@12f69cborg.highwire.dtl.DTLVardef@1cac774org.highwire.dtl.DTLVardef@1ec99ccorg.highwire.dtl.DTLVardef@652c59_HPS_FORMAT_FIGEXP M_FIG C_FIG