Coding region: Difference between revisions

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== 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 product mRNA (teal).]]

In [[DNA]], the coding region is flanked by the [[Promoter (genetics)|promoter sequence]] on the 35' end of the [[template strand]] and the termination sequence on the 53' 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 <nowiki>https://www.khanacademy.org/science/biology/gene-expression-central-dogma/transcription-of-dna-into-rna/a/overview-of-transcription</nowiki>.</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|url-status=live|archive-url=|archive-date=|access-date=}}</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.