Xenobiology (XB) is a subfield of synthetic biology, the study of synthesizing and manipulating biological devices and systems.[1] The name "xenobiology" derives from the Greek word xenos, which means "stranger, alien". Xenobiology is a form of biology that is not (yet) familiar to science and is not found in nature.[2] In practice, it describes novel biological systems and biochemistries that differ from the canonical DNA–RNA-20 amino acid system (see central dogma of molecular biology). For example, instead of DNA or RNA, XB explores nucleic acid analogues, termed xeno nucleic acid (XNA) as information carriers.[3] It also focuses on an expanded genetic code[4] and the incorporation of non-proteinogenic amino acids, or “xeno amino acids” into proteins.[5][6]
^Pinheiro, V.B.; Holliger, P. (2012). "The XNA world: Progress towards replication and evolution of synthetic genetic polymers". Current Opinion in Chemical Biology. 16 (3–4): 245–52. doi:10.1016/j.cbpa.2012.05.198. PMID22704981.
^Bain, J. D.; Switzer, C.; Chamberlin, R.; Benner, Steven A. (1992). "Ribosome-mediated incorporation of a non-standard amino acid into a peptide through expansion of the genetic code". Nature. 356 (6369): 537–39. Bibcode:1992Natur.356..537B. doi:10.1038/356537a0. PMID1560827. S2CID4286160.
^Noren, C.J.; Anthony-Cahill, S.J.; Griffith, M.C.; Schultz, P.G. (1989). "A general method for site-specific incorporation of unnatural amino acids into proteins". Science. 244 (4901): 182–88. Bibcode:1989Sci...244..182N. doi:10.1126/science.2649980. PMID2649980.