5n8p is a 6 chain structure with sequence from Caulobacter crescentus cb15. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
[SLAP_CAUCR] The S-layer is a paracrystalline mono-layered assembly of proteins which coats the surface of bacteria. Probably acts as a physical barrier to parasites and lytic enzymes.