def get_sequence(pdbfile):
    """Return Aminoacid Sequence as list"""
    seq = []
    oresnum = -1
    for line in open(pdbfile, 'r'):
        if line[:4] != 'ATOM':
            continue
        resnum = int(line[22:26])
        if resnum != oresnum:
            seq.append(line[17:20])
        oresnum = resnum
    return seq