Mantle (geology) might possibly be exposed in the South Pole-Aitken basin and/or the Crisium basin. The lunar mantle contains a seismic discontinuity at ~500 km depth, most likely related to a change in composition. Titan and Triton each have a mantle made of ice or other solid volatile substances. Some of the largest asteroids have mantles; for example, Vesta has a silicate mantle similar in composition to diogenite meteorites. Mantle (geology) The mantle is a layer inside a planetary body bounded below by a core and above by a crust. Mantles are made of rock or ices, and are generally the largest
S-layer three (p3), four (p4), or six (p6) identical protein subunits. The center-to-center spacing (or unit cell dimensions) between these subunits range from 4 to 35 nm. Assembly of a highly ordered coherent monomolecular S-layer array on a growing cell surface requires a continuous synthesis of a surplus of S-layer proteins and their translocation to sites of lattice growth. Moreover, information concerning this dynamic process were obtained from reconstitution experiments with isolated S-layer subunits on cell surfaces from which they had been removed (homologous reattachment) or on those of other organisms (heterologous reattachment). S-layer proteins have the natural capability to self-assemble