def Grab_Sequence( reader ):
    """ given reader is the position after a fasta header, extract a sequence
        return the last line read and the sequence
    """
    #read and concatenate lines until > found or other non-sequence character found
    total_sequence = ''
    sequence = reader.readline( )
    while( sequence != '' and sequence.find( '>' ) == -1 ):
        total_sequence = total_sequence + sequence
        sequence = reader.readline()
    total_sequence = total_sequence.replace( '\n', '' )
    total_sequence = total_sequence.replace( '*', '' )
    return sequence, total_sequence