def reverse_compliment(dna):
    DNA = dna.upper()
    rcom = []
    for i in dna:
        if i == 'A':
            rcom.append('T')
        elif i == 'T':
            rcom.append('A')
        elif i == 'G':
            rcom.append('C')
        elif i == 'C':
            rcom.append('G')
    r = rcom[::-1]
    reversedna = ''.join(r)
    return reversedna