Editing Operon (section)

== Overview ==
{{Prokaryote_gene_structure}}
Operons occur primarily in [[prokaryote]]s but also rarely in some [[eukaryote]]s, including [[nematode]]s such as [[Caenorhabditis elegans|''C. elegans'']] and the fruit fly, [[Drosophila|''Drosophila melanogaster'']].<ref name="Kominek"/> [[Ribosomal RNA|rRNA]] genes often exist in operons that have been found in a range of eukaryotes including [[chordate]]s. An operon is made up of several [[structural gene]]s arranged under a common [[promoter (biology)|promoter]] and regulated by a common operator. It is defined as a set of adjacent structural genes, plus the adjacent regulatory signals that affect transcription of the structural genes.<sup>5</sup><ref>{{cite book |vauthors=Miller JH, Suzuki DT, Griffiths AJ, Lewontin RC, Wessler SR, Gelbart WM |title=Introduction to genetic analysis |url=https://archive.org/details/solutionsmanualf0000fixs_u8x1 |url-access=registration |publisher=W.H. Freeman |location=San Francisco |year=2005 |pages=740 |isbn=978-0-7167-4939-4 |edition=8th }}</ref> The regulators of a given operon, including [[repressor]]s, [[Corepressor (genetics)|corepressor]]s, and [[Activator (genetics)|activator]]s, are not necessarily coded for by that operon. The location and condition of the regulators, promoter, operator and structural DNA sequences can determine the effects of common mutations.

Operons are related to [[regulon]]s, [[stimulon]]s and [[modulon]]s; whereas operons contain a set of genes regulated by the same operator, regulons contain a set of genes under regulation by a single regulatory protein, and stimulons contain a set of genes under regulation by a single cell stimulus.  According to its authors, the term "operon" is derived from the verb "to operate".<ref>{{cite journal | vauthors = Jacob F | title = The birth of the operon | journal = Science | volume = 332 | issue = 6031 | pages = 767 | date = May 2011 | pmid = 21566161 | doi = 10.1126/science.1207943 | author-link = François Jacob | bibcode = 2011Sci...332..767J | doi-access = free }}</ref>