BIOL 200 Lecture Notes - Lecture 25: Aminoacyl-Trna, Transcription Preinitiation Complex, 5.8S Ribosomal Rna
Document Summary
Transcribed by rna pol iii; then processed to form mature trna. Cca added to 3" end (5" cca 3"; this is the amino acid attachment site) Diagramed: pre and post processing forms of trna. Note the h-bonds b/w paired bases -> 3d structure of trna. There are 20 aminoacyl-trna synthetases: each binds to a trna that codes for a specific aa (one aminoacyl-trna synthetase for each aa). The synthetase would bind to any trna that codes for the aa. More than one trnas can code for the same aa (anticodon wobble) Result: phe is selected by its codon aa linked to trna via high-energy ester bond rrna = ~80% of total cellular rna. Constant transcription of rrna units rrna has stem-loop structure: highly conserved among species (recall map diagram) 16s bacterial rrna is similar to 18s eukaryotic rna. 50s subunit = 23s + 5s + 31 proteins. 50s + 30s = 70s (70s = assembled ribosome)
