def format_fasta(header, sequence, line_length=60):
    """Format sequence as in fasta with leading '>'.

    Args:
        header (str): description.
        sequence (str): sequence to wrap over lines.
        line_length (int, optional): line break. Defaults to 80.

    Returns:
        str: fasta file entry.
    """
    lines = ['>{header}\n'.format(header=header)]
    for i in range(0, len(sequence), line_length):
        lines.append(sequence[i:i + line_length] + '\n')
    return ''.join(lines)
