def split_proj_name(proj_name):
    """Split projection name.

    Projections named as follows: ${transcript_ID}.{$chain_id}.
    This function splits projection back into transcript and chain ids.
    We cannot just use split("."), because there might be dots
    in the original transcript ID.
    """
    proj_name_split = proj_name.split(".")
    q_num_str = proj_name_split[-1]
    trans_name = ".".join(proj_name_split[:-1])
    return trans_name, q_num_str