(a) In order to calculate a multiple sequence alignment for N sequences, how many pair- wise alignments have to be calculated?
(b) Align the following using “star alignment” showing all intermediate steps:
a) 2 at a time.
b) To calculate the ‘center’ sequence, we compute all the pairwise alignment scores. Assume these pairwise alignment scores are givenin the following matrix
Summing pairwise scores in each row in the matrix, we obtain that "S_1" is closest to all the other sequences. Hence, "S_1" is selected to be at the center of the star.