Different aa-tRNAs Are Selected Uniformly on the Ribosome

jerry submitted, created time 5 months 3 weeks (www.molecule.org)

Ten E. coli aminoacyl-tRNAs (aa-tRNAs) were assessed for their ability to decode cognate codons on E. coli ribosomes by using three assays that evaluate the key steps in the decoding pathway. Despite a wide variety of structural features, each aa-tRNA exhibited similar kinetic and thermodynamic properties in each assay

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The mechanics of translocation

jerry submitted, created time 7 months 6 days (www.sciencedirect.com)

Stepwise addition of amino acids to the growing polypeptide chain requires the coordinated movement of mRNA and tRNAs through the ribosome, a process known as translocation. Researchers review current understanding of the kinetics and mechanics of translocation, with emphasis on the structure of a functional mammalian ribosome stalled during translocation by an mRNA pseudoknot.

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New role for tRNAs

sea-maid submitted, created time 7 months 3 weeks (www.pnas.org)

tRNA sequences can mediate the cis- and trans-splicing of mRNAs. From this study, we can see that the hybrid RNAs are spliced at the specific pretRNA splicing sites, releasing both functional tRNAs that suppress nonsense mutations and translatable mRNAs that activate the signal transduction pathway.

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Life without RNase P.

kavin submitted, created time 8 months 2 days (www.ncbi.nlm.nih.gov)

The universality of ribonuclease P (RNase P), the ribonucleoprotein essential for transfer RNA (tRNA) 5' maturation, is challenged in the archaeon Nanoarchaeum equitans. In this study, the researchers's findings demonstrate how nature can cope with the loss of the universal and supposedly ancient RNase P through genomic rearrangement at tRNA genes under the pressure of genome condensation.

3 comments | Blog It | Email It | Keywords: transfer RNA tRNA splicing Nanoarchaeum equitans tRNA tRNA stability RNase P RNA

Mining prokaryotic genomes for unknown amino acids: a stop-codon-based approach

DanyC submitted, created time 1 year 6 months (www.biomedcentral.com)

"This result suggests that the unknown amino acid encoded by stop codons does not exist, or its phylogenetic distribution is rather limited, which is in agreement with the previous study on tRNA. The method described here can be used in future studies to explore novel readthrough events from complete genomes, which are rapidly growing."

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