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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How cells save their energy

Position of eukaryotic initiation factor eIF5B on the 80S ribosome mapped by directed hydroxyl radical probing

addict submitted, created time 1 year 6 months (www.nature.com)

Eukaryotic translation initiation factor eIF5B is a ribosome-dependent GTPase that mediates displacement of initiation factors from the 40S ribosomal subunit in 48S initiation complexes and joining of 40S and 60S subunits. Here, we determined eIF5B's position on 80S ribosomes by directed hydroxyl radical cleavage

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RF3 Induces Ribosomal Conformational Changes Responsible for Dissociation of Class I Release Factors

crackpot submitted, created time 1 year 6 months (www.cancercell.org)

"During translation termination, class II release factor RF3 binds to the ribosome to promote rapid dissociation of a class I release factor (RF) in a GTP-dependent manner. We present the crystal structure of E. coli RF3•GDP, which has a three-domain architecture strikingly similar to the structure of EF-Tu•GTP. Biochemical data on RF3 mutants show that a surface region involving domains II and III is important for distinct steps in the action cycle of RF3. Furthermore, we present a cryo-electron microscopy (cryo-EM) structure of the posttermination ribosome bound with RF3 in the GTP form

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An Antisense RNA Inhibits Translation by Competing with Standby Ribosomes

athena submitted, created time 1 year 7 months (www.molecule.org)

"Most antisense RNAs in bacteria inhibit translation by competing with ribosomes for translation initiation regions (TIRs) on nascent mRNA. We propose a mechanism by which an antisense RNA inhibits translation without binding directly to a TIR. The tisAB locus encodes an SOS-induced toxin, and IstR-1 is the antisense RNA that counteracts toxicity. We show that full-length tisAB mRNA (+1) is translationally inactive and endonucleolytic processing produces an active mRNA (+42)

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The leader region of Laminin B1 mRNA confers cap-independent translation

athena submitted, created time 1 year 8 months (nar.oxfordjournals.org)

"Translation initiation of eukaryotic mRNAs generally occurs by cap-dependent ribosome scanning. However, certain mRNAs contain internal ribosome entry sites (IRES) allowing cap-independent translation."

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Ribosomal Protein L3: Gatekeeper to the A Site

alpha submitted, created time 1 year 9 months (www.molecule.org)

"Ribosomal protein L3 (L3) is an essential and indispensable component for formation of the peptidyltransferase center. Atomic resolution ribosome structures reveal two extensions of L3 protruding deep into the core of the large subunit. The central extension of L3 in Saccharomyces cerevisiae was investigated using a combination of molecular genetic, biochemical, chemical probing, and molecular modeling methods. "

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RIBOSOME DYNAMICS: Insights from Atomic Structure Modeling into Cryo-Electron Microscopy Maps

biscuits submitted, created time 1 year 11 months (arjournals.annualreviews.org)

Interpretation of cryo-EM reconstructions of the ribosome in quasi-atomic detail reveals a picture in which the ribosome uses RNA not only to catalyze chemical reactions, but also as a means for signal transduction over large distances.

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