BIO230H1 Lecture 7: Lecture 7 Readings
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BIO230H1 Full Course Notes
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It always carries the amino acid methionine, forming the complex met-trnai. Eucaryotic initiation factor (eif): protein that help load initiator trna on to the ribosome, thus initiating translation. Ribosomal unit moves 5" to 5" searching for aug. Sometimes leaky scanning can occur, where the unit misses the aug. In bacteria, mrna does not have 5" cap to signal where to start searching for start of translation. They contain shine-dalgarmo sequence, located a few nucleotides upstream from aug, where translation begins. Some proteins begin to fold while still being synthesized. Translation of an mrna sequence into an amino acid sequence on the ribosome is not the end process of forming a protein. To function, the completed polypeptide chain must fold correctly into its three-dimensional conformation, bind any cofactors required, and assemble with its partner protein chains. Many proteins require covalent modifications of selected amino acids. Co-translational protein folding: growing polypeptide chain acquires secondary and tertiary structure as it emerges from ribosome.
