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N Sonenberg

Publications and source records attributed to N Sonenberg.

278 records · Page 16Linked to original sources
PubMed1975

Identification of a region in 23S rRNA located at the peptidyl transferase center.

A photolyzable derivative of dipeptidyl-tRNA, p-azido-N-tBoc-Phe-[3H]Phe-tRNA, bound reversibly to 70S ribosomes in the presence of poly(U), becomes, when irradiated, covalently attached to components of the 50S ribosomal subunit. Most of the reaction occurs within the 23S RNA, while ribosomal proteins are only weakly labeled. Reversible binding as well as the covalent reaction are reduced in the absence of poly(U) or in the presence of several antibiotics specific for the 50S ribosomal subunit. There are apparently few sites (or perhaps a single site) of reaction on the 23S RNA that are exclusively located within the 2000 nucleotides from the 3 terminus of the molecule. Part of the 23S RNA within this region must therefore be closely associated with the peptidyl transferase center of the ribosome.

Binding Sites↗
PubMed1973

Mapping of Escherichia coli ribosomal components involved in peptidyl transferase activity.

The method of affinity labeling has been used to identify protein components of 50S ribosomal subunits involved in peptidyl transferase activity. E. coli 50S ribosomal subunits were mapped by reaction with the N-bromoacetyl analog of chloramphenicol, an antibiotic known to interact specifically with the active center of the enzyme. The synthetic analog competes with chloramphenicol in binding to 50S ribosomal subunits and inhibits peptidyl transferase activity. It attaches covalently to the ribosome under appropriate conditions and causes an irreversible loss in peptidyl transferase activity. The reagent specifically alkylates cysteine residues of proteins L2 and L27.

Acetamides↗
PubMedDate not supplied

Sequence of reovirus haemagglutinin predicts a coiled-coil structure.

The use of modern techniques has led to new insights into the molecular mechanisms of viral pathogenesis. Although the infectious process is quite complex, it is clear that one critical stage, the interaction of viral attachment proteins with cell-surface receptors, often has a major role in determining the pattern of infection. The mammalian reoviruses have served as useful models for understanding the molecular basis of viral pathogenesis. The mammalian reovirus haemagglutinin (sigma 1 protein), which is an outer capsid protein, has been shown to be a major factor in determining virus-host cell interactions. To further our understanding of the structure and function of the haemagglutinin, we have cloned a complementary DNA copy of the reovirus type 3 S1 double-stranded RNA gene which encodes the virus haemagglutinin and have sequenced the DNA complementary to the S1 gene. Analysis of the predicted amino-acid sequence of the virus haemagglutinin has allowed us to determine that the amino-terminal portion contains an alpha-helical coiled-coil structure and that the carboxy-terminal portion contains the receptor-interacting domains. Using this information, we propose here a model of how the reovirus haemagglutinin is attached to the virus particle.

Amino Acid Sequence↗