def get_start_end_pl_surr(TMD_start, TMD_end, seqlen, surr):
    """Get start and end of TMD plus surrounding sequence

    Parameters
    ----------
    TMD_start
    TMD_end
    seqlen
    surr

    Returns
    -------

    """
    TMD_start_pl_surr = TMD_start - surr
    if TMD_start_pl_surr < 1:
        TMD_start_pl_surr = 1
    TMD_end_pl_surr = TMD_end + surr
    if TMD_end_pl_surr > seqlen:
        TMD_end_pl_surr = seqlen
    return TMD_start_pl_surr, TMD_end_pl_surr
