Affinity labeling of the ribosomal P site in Drosophila melanogaster
Several recent studies have probed the peptidyl transferase region of the Drosophila ribosome via the use of reactive site specific analogues (affinity labels). P site proteins adjacent to the 3' end of the amino acid bearing tRNA strand were labeled with modified tRNA fragments. Drugs affecting the binding of these agents were used to further clarify the nature of the region. The nascent peptide region of the P site was not labeled in previous experiments. To label that region radioactive Bromoacetylphenylalanyl-tRNA (BrAcphe-tRNA) was synthesized. The alpha-bromoacetyl group of this analogue is potentially reactive with nucleophiles present in either proteins or RNAs. Charged tRNAs and tRNA analogues bearing a peptide bond on the N-terminus of their amino acid are recognized as having affinity for the ribosomal P site. Specific labeling of the P site by BrAcphe-tRNA was confirmed by its ability to radioactively label proteins indirectly. As many as 8 ribosomal proteins may be labeled under these conditions, however, the majority of the bound label is associated with 3 large subunit proteins and 2 small subunit proteins. Overlaps between the proteins labeled by BrAcphe-tRNA and those labeled by other affinity labels are examined and a model of the peptidyl transferase region of Drosophila ribosomes is presented.
- Research Organization:
- University of Southern California, Los Angeles (USA)
- OSTI ID:
- 6902298
- Resource Relation:
- Other Information: Thesis (Ph. D.)
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
PEPTIDES
LABELLING
AFFINITY
DROSOPHILA
RADIOISOTOPES
RIBOSOMES
TRACER TECHNIQUES
TRANSFER RNA
TRANSFERASES
ANIMALS
ARTHROPODS
CELL CONSTITUENTS
DIPTERA
ENZYMES
FLIES
FRUIT FLIES
INSECTS
INVERTEBRATES
ISOTOPE APPLICATIONS
ISOTOPES
NUCLEIC ACIDS
ORGANIC COMPOUNDS
ORGANOIDS
PROTEINS
RNA
550201* - Biochemistry- Tracer Techniques