Editing Coding region (section)

== Structure and function ==
[[File:Coding Region in DNA.png|thumb|398x398px|'''Transcription''': RNA Polymerase (RNAP) uses a template DNA strand and begins coding at the promoter sequence (green) and ends at the terminator sequence (red) in order to encompass the entire coding region into the pre-mRNA (teal). The pre-mRNA is polymerised 5' to 3' and the template DNA read 3' to 5']] [[File:Transcription label en.jpg|thumb|An electron-micrograph of DNA strands decorated by hundreds of RNAP molecules too small to be resolved. Each RNAP is transcribing an RNA strand, which can be seen branching off from the DNA. "Begin" indicates the 3' end of the DNA, where RNAP initiates transcription; "End" indicates the 5' end, where the longer RNA molecules are completely transcribed.]]
In [[DNA]], the coding region is flanked by the [[Promoter (genetics)|promoter sequence]] on the 5' end of the [[template strand]] and the termination sequence on the 3' end. During [[Transcription (biology)|transcription]], the [[RNA Polymerase|RNA Polymerase (RNAP)]] binds to the promoter sequence and moves along the template strand to the coding region. RNAP then adds RNA [[nucleotide]]s complementary to the coding region in order to form the [[mRNA]], substituting [[uracil]] in place of [[thymine]].<ref name=":2">Overview of transcription. (n.d.). Retrieved from https://www.khanacademy.org/science/biology/gene-expression-central-dogma/transcription-of-dna-into-rna/a/overview-of-transcription .</ref> This continues until the RNAP reaches the termination sequence.<ref name=":2" />

After transcription and maturation, the [[mature mRNA]] formed encompasses multiple parts important for its eventual translation into [[protein]]. The coding region in an mRNA is flanked by the [[Five prime untranslated region|5' untranslated region]] (5'-UTR) and [[Three prime untranslated region|3' untranslated region]] (3'-UTR),<ref name=":12"/> the [[Five-prime cap|5' cap]], and [[Poly a tail|Poly-A tail]]. During [[Translation (biology)|translation]], the [[ribosome]] facilitates the attachment of the [[Transfer RNA|tRNAs]] to the coding region, 3 nucleotides at a time ([[codons]]).<ref>{{Cite web|url=https://www.nature.com/scitable/topicpage/translation-dna-to-mrna-to-protein-393/|title=Translation: DNA to mRNA to Protein|last=Clancy|first=Suzanne|date=2008|website=Scitable: By Nature Education}}</ref> The tRNAs transfer their associated [[amino acid]]s to the growing [[polypeptide]] chain, eventually forming the protein defined in the initial DNA coding region. 
[[File:Mature_mRNA.png|thumb|413x413px|The coding region (teal) is flanked by untranslated regions, the 5' cap, and the poly(A) tail which together form the '''mature mRNA'''.<ref>{{Citation|last=Plociam|title=English: The structure of a mature eukaryotic mRNA. A fully processed mRNA includes the 5' cap, 5' UTR, coding region, 3' UTR, and poly(A) tail.|date=2005-08-08|url=https://commons.wikimedia.org/wiki/File:Mature_mRNA.png|access-date=2019-11-19}}</ref>]]