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Mystery Sequence
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Problem Set 4
Study Question 3
What is the minimum number of bases to specify the number of different amino acids found in protein?
G A C T
1 base fixed length nonoverlapping
Study Question 3
What is the minimum number of bases to specify the number of different amino acids found in protein?
2 base, fixed length, nonoverlapping
Study Question 3What is the minimum number of bases to specify the
number of different amino acids found in protein?
3 base, fixed length, nonoverlapping
Growth of E. coli on a plate
Growth of E. coli on a plate
Growth of E. coli on a plate
Growth of E. coli on a plate
Growth of E. coli on a plate
Growth of E. coli on a plate
Growth of E. coli on a plate
Infection by phage T4
Infection by phage T4
Infection by phage T4
Growth of E. coli B + phage T4
Seed plate withE.coli B and
phage T4(not visible)
Growth of E. coli B + phage T4
Growth of E. coli B + phage T4
Growth of E. coli B + phage T4
Growth of E. coli B + phage T4
Growth of E. coli B + phage T4
rII region of phage T4
rII rII
T4 rII+ T4 rII -
T4 DNA T4 DNA
rIIA rIIB rIIA- rIIB
Distinguishing T4 rII+ from rII-
T4 rII+
T4 rII -E. coli B x T4 rII+
T4 rII -E. coli K() x
T4 rII - cannot grow on E. coli K()
Why is T4rII- defective?
T4 rII -
T4 rII+
E. coli K()
E. coli K()
No infection
Lysis
Crick et al frameshift experiment
rIIA-
rIIA-
rIIA-
rIIA+
proflavin
proflavin
proflavin
How to explain frameshift results?Role of proflavin in experiment
CACTCGGATA
CACTCG??GATA
GTGAGC
GTGAGCAC
Proflavin causes one base insertions
(or deletions)
How to explain frameshift results?Wild type rIIA
rIIA+
… THE FAT CAT ATE THE BIG RAT...
Wld type rIIA
How to explain frameshift results?Single frameshift
rIIA-
THE FAT CAR TAT ETH EBI GRA …
… THE FAT CAT ATE THE BIG RAT...
How to explain frameshift results?Double frameshift
rIIA-
… THE FAT CAR TAT ETH EBI GRA …
… THE FAT CAT ATE THE BIG RAT...
… THE FAT CAR TAR TET HEB IGR …
How to explain frameshift results?Triple frameshift
rIIA-
… THE FAT CAR TAT ETH EBI GRA …
… THE FAT CAT ATE THE BIG RAT...
… THE FAT CAR TAR TET HEB IGR …
… THE FAT CAR TAR TOE THE BIG ...
Study Question 7
When will proflavin-induced mutation suppress?
Study Question 8
Results of frameshift experiment if variable length code?
This is a variable length code
This is a varitable length code
Variable length code with GATC?
