Ribosomal proteins

Initiation factor 2 (IF2) guides the ribosome to the elongation phase of protein synthesis. Here, Basu et al. provide structural insights into how compact IF2-GDP makes way for initiator tRNA accommodation into the peptidyl (P) site of the ribosome.

AlphaFold-assisted CryoEM structure determination reveals the Bfr2-Lcp5 complex structure in the yeast 90S pre-ribosome.

Mitochondrial ribosomes (mitoribosomes) are characterized by a distinct architecture and thus biogenesis pathway. Here, cryo-EM structures of mitoribosome large subunit assembly intermediates elucidate final steps of 16 S rRNA folding, methylation and peptidyl transferase centre (PTC) completion, as well as functions of several mitoribosome assembly factors.

Maturation of the ribosomal peptidyl transferase center (PTC) is mediated by universally conserved GTPases. Here, cryo-EM structures of mitochondrial ribosomal large subunit assembly intermediates and of mature ribosomes offer insight into the roles of several assembly factors, including GTPBP6’s role in both ribosome biogenesis and recycling.

Golkar, Bassenden et al. report two structures of the latest generation aminoglycoside antibiotic plazomicin in complex with the bacterial 70S ribosome as well as in complex with AAC(2’)-la acetyltransferase, an antibiotic modification enzyme (AME). Their study can be useful in the development of newer aminoglycosides that are not modified by AMEs while being capable of targeting the bacterial ribosome.

eIF5A is critical for protein synthesis but has not yet been associated with congenital human disease. Here, the authors show that EIF5A variants cause a Mendelian disorder via reduced eIF5A-ribosome interactions and this phenotype is partially corrected by spermidine supplementation in yeast and zebrafish.