Complex sentence: The structure of LSU in 3-dimensions shows one relatively smooth surface and the opposite surface having three projections, notably the L1 protuberance, the central protuberance, and the L7/L12 stalk.
Split into simpler sentences: The structure of the large ribosomal subunit in 3-dimensions shows one surface that is relatively smooth and the opposite surface with three projections. These projections are known as the L1 protuberance, the central protuberance, and the L7/L12 stalk.