1. Protein Synthesis

2. Ribosomes

4. 16S rRNA Secondary Structures

5. 30S Subunit Structure: 16S rRNA & proteins

7. Electron Density Models of Both Subunits & tRNAs

8. 70S Ribosome Showing tRNAs in A, P & E Sites

9. Prokaryotic Ribosomes

10. tRNA Structure

12. Modified Bases

13. Codon - Anticodon Base-Pairing - Role of Wobble Bases

14. The Genetic Code

15. Aminoacyl Transferase Determines Specificity of Amino Acid Inserted at a Codon

16. Aminoacyl-tRNA Synthetase Function

17. Aminoacyl tRNA Synthetase Structure

18. Chemistry of Aminoacylation

19. Roles of Eukaryotic Initiation Factors eIF-1 Promotes dissociation of 80S ribosomes Binds after eIF-4 and allows scanning to begin eIF-2 GTPase activated by 60S subunit binding Stabilizes binding of initiator met- tRNA i met eIF-3 Promotes 80S ribosome dissociation Binds to 40S subunit & prevents reassociation of 60S subunit Promotes binding of eIF-2 eIF-4 Multi-component complex Recruits mRNA binding Recognizes cap, pA tail Promotes binding of eIF-1 for scanning eIF-5 Promotes reformation of 80S ribosome Displaces eIF-6 eIF-6 Promotes dissociation of 80S ribosome Binds 60S subunit & prevents reassociation with 40S subunit

20. Translation Initiation

21. eIF-1 + eIF-6 eIF-1 + eIF3 Steps in Eukaryotic Translation Initiation eIF-6

22. eIF4 Complex Components & Functions eIF4E – Cap binding eIF4G – eIF3 binding PAB1P binding eIF4A – helicase eIF4B – stimulates RNA binding of eIF4A

23. Scanning Model of Eukaryotic Translation Initiation Requirements: Must be able to determine which AUG is the right one to start translation

24. Kozack Consensus CCRCCAUGG

25. Overview of Elongation

26. Elongation Step 1: Binding of aa-tRNA Eukaryotic counterparts: EF1  EF1 

27. TC=EF1  ·GTP ·aa-tRNA Kinetics of First Elongation Step Allow Proofreading Rib = ribosome + met-tRNA i met

28. Peptidyl Transferase is Large Ribosomal Subunit

29. Peptidyl Transferase Active Site & Reaction Mechanism

30. GTP Hydrolysis Is Required for Translocation Eukaryotic counterpart: EF-2

31. Structure of EF-G Compared to EF-TutRNA Complex EF-TutRNA EF-G

32. Overview of Elongation

33. Elongation

34. Translocation

35. Similarity Between eRF1 Tertiary Structure and tRNA

36. Termination Factors RF-3 & eRF-2 RF-3 – Prokaryotic eRF-2 – Eukaryotic Are GTPases that catalyzes the actual cleavage of the pep- tRNA bond to release the peptide

37. Protein Folding