1. Biochemistry Chen Yonggang Zhejiang University Schools of Medicine

2. Translation, making protein following nucleic acid directions

3. Bodega Bay, Sonoma County

4. Breakfast at The Tides, Bodega Bay

7. The Genetic Code

10. Ribosomes are ribonucleoprotein complexes table 6.7 Small subunit Large Subunit PROCARYOTIC EUCARYOTIC 70 S 30S 50S RNA 5S, 16S, 23S PROTEINS 55 80 S 40S 60S RNA 5S, 5.8S,18S,28S PROTEINS 84

14. The first step involves forming an enzyme-bound aminoacyl adenylate The hydrolysis of the PPi makes the process irriversible

15. The second step transfers the amino acid to the 3’OH of the tRNA, retaining the energy of the adenylate

16. tRNAs fold into L-shaped structures Figure 2.59

19. Wobble allows one codon to base pair with up to three anticodons Base stacking in the anticodon assures that bases 2 and 3 of the anticodon will follow Watson-Crick rules. Base 1 can wobble

21. Thus 31 tRNAs can read 61 codons

23. Initiation A common mechanism

27. In procaryotes IFs 1,2 and 3 are needed to begin IF-3 is an 30S anti-association factor IF-2 binds and preps initiator AA-tRNA IF-1 is a GTP binding hydrolase These allow the association of the 30S, Met-tRNA metF and factors to bind in preparation for mRNA and 50S binding

29. Initiation is similar for pro- and eucaryotes Devlin 6.7

31. Devlin 6.7 Eucaryotic initiation is similar

33. The association of all initation components creates a 70S ribosome with initiator tRNA in the P site

34. Elongation A repeated experience

41. In procaryotes, under the control of EF-T, a second aminoacyl-tRNA is bound in the A site

42. Devlin 6.8 In eucaryotes similar events occur

45. Peptidyl transferase synthesizes a peptide bond forming a dipeptide

46. The peptide bond is formed using the energy derived from the aminoacyl ester bond and moves the peptide to the A site-bound Aminoacyl-tRNA

48. EF-G mediated GTP hydrolysis translocates the mRNA and peptidyl-tRNA expelling the spent tRNA

49. Devlin 6.8 Eucaryotic translocation is similar

50. This elongation cycle is repeated as many times as there are codons

51. EF-T/1 mediated binding is followed peptide bond formation and EF-G/2 mediated peptidyl transfer

52. Eucaryotic elongation is similar to the procaryotic process

53. The growing polypeptide chain remains attached to the last tRNA added The next codon is UAG

56. Devlin 6.10

61. Because of differences in translation bacterial growth can be inhibited by antibiotics Devlin 6.8