Do some key checks as pbuilder hook seemingly messes autopkgtest

revcomp = lambda x: ''.join([{'A':'T','C':'G','G':'C','T':'A'}[B] for B in x][::-1])

def normalize(seq):

    if seq == 'A' or seq == 'C' or seq == 'G' or seq == 'T':

        rev = revcomp(seq)

        return min(rev,seq)