2.3.4 Aminoacid sequences and base sequences

In this lecture we will check how we can find base sequences starting from aminoacid sequences. Suppose you detected the following protein during a study:

MADINA*

How can this protein be generated?

1 Question 1

How long is the base sequence generating this protein? How many possible base sequences can result in this aminocid sequence?

2 Question 2

Write all the possible base sequences resulting in this aminoacid table, as a table with 7 columns, with the possible codons in each column.

3 Question 3

Choose three of the sequences found in the previous question. In RStudio, load seqin:

> library(seqinr)

and show that these four sequences indeed translate to the protein we want. An example:

> translate(s2c("AAA"))
[1] "K"

Replace AAA with the chosen sequences.

4 Question 4

Write a base sequence containing one of the sequences above in an open reading frame in second position. Do the same for the third position.