1. Translation Initiation Elongation Termination
AAAAAn
7mG
Initiation
Recruitment of mRNA to the ribosome
Elongation
Synthesis of nacent polypeptide
Termination
Release of polypeptide from the ribosome
7mG
nAAAAA
7mG
nAAAAA

2. Eukaryotic Ribosome Structure
Large Subunit
80S
Small Subunit
40S
Large subunit Small subunit
rRNA: S, 5.8S and 5S S
Proteins:

3. •Component of the Active Site of the Ribosome
P-protein Stalk of the Large Ribosomal Subunit
•Universal Feature
•Component of the Active Site of the Ribosome
•Stimulate EF2-GTPase activity
• P0 + (P1 + P2)2
P0: 35 kDa
P1 and P2: ~12 kDa
60S
28S rRNA

4. Characteristic P-protein
Variable N-terminus
Acidic Hinge
Conserved C-terminus

5. P-protein Complexity Bacteria Rat Yeast P1a P1 P1 P1b L12 P2a P2 P2

6. Plant Ribosomes Contain Four Distinct
12-kDa P-proteins
ESDDDMGFSLFD
ESDDDMGFSLFD
ESDEDMGFSLFD
KSDDDMGFSLFD
Variable N-terminus
Acidic
Hinge
Conserved
C-terminus

7. P-protein Complexity Bacteria Rat Yeast Plants P1 P2 P3 P1 P1a P1 P1b

8. X Regulatory Role of P-proteins in Translation
Slow Growth of Yeast P-protein Deficient Mutants
Wild type + P-proteins
Mutants No P-proteins X

9. Regulatory Role of P-proteins in Translation
Ribosomes of Actively Dividing Yeast Cells Contain More P-proteins than Ribosomes of Cells in the Stationary Phase
Stationary Phase
log Phase

10. Arabidopsis: A model plant system
•Genome sequenced
•Rapid life cycle
•Easy to grow
•LOTS of seed
•Genetic “tools” available
•Large number of mutants available
"What is a weed? A plant whose virtues have not yet been discovered." Ralph Waldo Emerson

11. Agrobacterium tumefaciens
Agrobacterium tumefaciens Infection
Plant Cell
Agrobacterium tumefaciens
T-DNA
Chromosome
Ti plasmid
Nucleus
Chromosomal DNA
T-DNA