Interbreeding between archaic and modern humans been shown that Neanderthal ancestry has been selected against in conserved biological pathways, such as RNA processing. Consistent with the hypothesis that purifying selection has reduced Neanderthal contribution in present-day modern human genomes, Upper Paleolithic Eurasian modern humans (such as the Tianyuan modern human) carry more Neanderthal DNA (about 4–5%) than present-day Eurasians modern humans (about 1–2%). Genes affecting keratin were found to have been introgressed from Neanderthals into modern humans (shown in East Asians and Europeans), suggesting that these genes gave a morphological adaptation in skin and hair to modern humans to cope with non-African environments. This is likewise
Methanosarcinales S-layer Tile Protein Methanosarcinales S-layer Tile Protein The Methanosarcinales S-layer Tile Protein (MSTP) is a protein family found almost exclusively in Methanomicrobia members of the order Methanosarcinales. Typically a tandem repeat of two DUF1608 domains are contained in a single MSTP protein chain and these proteins self-assemble into the protective proteinaceous surface layer (S-layer) structure that encompasses the cell. The S-layer, which is found in most Archaea, and in many bacteria, serves many crucial functions including protection from deleterious extracellular substances. The first S-layers were discovered in bacteria in the 1950s and the presence of S-layers in many Archaea was determined through microscopic