def parse_role_links(role_links_filename):
    """
    Parse TIGRFAMS_ROLE_LINK.
    """
    tigrfam_role = {}
    with open(role_links_filename) as f:
        for line in f:
            tigrfam, role = line.strip().split()
            tigrfam_role[tigrfam] = role
    return tigrfam_role