Question

The following sequence represents the DNA template strand of a gene.

3′-TAC TGT GTC TCC CAC CGA ACT-5′

nucleotide number 1 21   

a. What is the mRNA transcribed from this sequence?

b. What is the amino acid sequence translated from the mRNA?

c. If there is a transition at nucleotide #7, what is the amino acid sequence?

d. What type of mutation is this (choose from frameshift, missense, nonsense, silent)?

e. If there is a transversion at nucleotide #6, what is the amino acid sequence (start with the original sequence, there is more than 1 correct answer)?

f. What type of mutation is this (choose from frameshift, missense, nonsense, silent)?

g. If there is a transition at nucleotide #10, what is the amino acid sequence (start with the original sequence)?

h. What type of mutation is this (choose from frameshift, missense, nonsense, silent)?

Answer 1

a&b).

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

21

DNA

T

A

C

T

G

T

G

T

C

T

C

C

C

A

C

C

G

A

A

C

T

mRNA

A

U

G

A

C

A

C

A

G

A

G

G

G

U

G

G

C

U

U

G

A

Amino acid

Met

Thr

Gln

Arg

Val

Ala

STOP

c&d).

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

21

DNA

T

A

C

T

G

T

A

T

C

T

C

C

C

A

C

C

G

A

A

C

T

mRNA

A

U

G

A

C

A

U

A

G

A

G

G

G

U

G

G

C

U

U

G

A

Amino acid

Met

Thr

STOP

Arg

Val

Ala

STOP

Effect: Nonsense mutation

e&f).

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

21

DNA

T

A

C

T

G

A

G

T

C

T

C

C

C

A

C

C

G

A

A

C

T

mRNA

A

U

G

A

C

U

C

A

G

A

G

G

G

U

G

G

C

U

U

G

A

Amino acid

Met

Thr

Gln

Arg

Val

Ala

STOP

Effect: Silent mutation

g&h).

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

21

DNA

T

A

C

T

G

T

G

T

C

C

C

C

C

A

C

C

G

A

A

C

T

mRNA

A

U

G

A

C

A

C

A

G

G

G

G

G

U

G

G

C

U

U

G

A

Amino acid

Met

Thr

Gln

Gly

Val

Ala

STOP

Effect: missense mutation