def get_model_chain_ids(structure):
    """ 
    Extracts model and chain ids from structure object.

    Parameters
    ----------
    structure: Bio.PDB.Structure.Structure

    Returns
    -------
    struct_id: tuple
        tuple of (modelid, chainid)
    """
    modelnum = []
    chainid = []
    for model in structure:
        modelnum.append(model.get_id())
        for chain in model:
            chainid.append(chain.get_id())

    struct_id = (modelnum[0], chainid[0])
    return struct_id