BIOL 2500 Lecture Notes - Lecture 22: Eukaryotic Initiation Factor, Transcription Preinitiation Complex, Start Codon
6 Apr 2017
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Document Summary
Aa in the order specifed by the codons. Polypeptide structure: polypeptides have four levels of organization, the sequence of aa in the polypeptide chain is the primary structure, teritary structure results from a variety of interactions involving the r-groups of different aa in. Secondary structures form due to hydrogen bonding between different amino acids in the chain. Secondary structure include the alpha helix and the beta pleated sheet the polypeptide chain: tertiary structure is dependent on primary and secondary structure, quaternary structure contains two or more polypeptides. Initiation begins when the small ribosomal subunit binds near the 5" end of the mrna and identifies the start codon. Finally, the large subunit joins the small subunit to form the intact ribosome and translation begins. In e. coli, six molecular components come together to initiate translation: mrna, the ribosomal subunit, the large subunit, the initiator trna, three initiation factor proteins, and gtp.
