Two general types of transcription factors have been defined\u00a0 namely ;<\/span><\/p>\r\n\r\n Enhancer regions are binding sequences,\u00a0 for specific transcription factors. [pb_glossary id=\"934\"]Enhancers[\/pb_glossary] may be located upstream or downstream of transcription start site. Each enhancer is made up of short DNA sequences called distal control elements<\/strong> . <\/span><\/p>\r\n Proteins called Activators\u00a0 , mediator proteins and transcription factors <\/strong>bind to the enhancers .When a transcription factor binds to its enhancer sequence, the shape of the\u00a0 transcription factor protein changes. This enables the transcription factor to\u00a0 \u00a0interact with proteins at the promoter site. <\/span><\/p>\r\n As the enhancer region may be distant from the promoter, the DNA must bend to allow the proteins at the two sites to come into contact. DNA bending proteins help to bend the DNA and bring the enhancer and promoter regions together.<\/span><\/p>\r\n \u00a0Two different genes may have the same promoter but different distal control elements, enabling differential gene expression.<\/span><\/p>\r\n \"Enhancers\" image<\/a> from Biology<\/em>, an OpenStax resource <\/a>is licensed under\u00a0CC BY 4.0<\/a><\/span><\/p>\r\n\r\n \u00a0The TATA box :<\/strong> This resembles the the -10 sequence element of bacterial promoters. This region contain the sequence TATAA\u00a0 and is located 25 to 30 nucleotides upstream of the transcription start site. <\/span><\/p>\r\n Initiator, or Inr, sequence : <\/strong>In addition to the TATA box ,<\/span> the promoters of many gene contain a second important sequence element called initiator, or Inr, sequence. Some RNA polymerase II promoters contain only an Inr element, with no TATA box.\u00a0<\/span><\/p>\r\n The promoter -proximal elements : The CAAT box<\/strong>, with the consensus sequence 5\u2019-CCAAT-3\u2019<\/strong> and the GC box,<\/strong> with the consensus sequence 5\u2019-GGGCGG-3\u2019. <\/strong>These\u00a0 promoter-proximal elements\u00a0 regulate gene transcription.<\/p>\r\n\r\n \"Eukaryotic Transcription Initiation\" image from the book General Biology (Boundless) <\/a>licensed under\u00a0CC BY-SA 4.0<\/a><\/span><\/p>\r\n\r\n \u00a0RNA polymerase II requires specific proteins <\/span>called transcription factors <\/strong><\/span>to initiate transcription <\/span>.\u00a0<\/span><\/p>\n Two general types of transcription factors have been defined\u00a0 namely ;<\/span><\/p>\n Enhancer regions are binding sequences,\u00a0 for specific transcription factors. Enhancers<\/a> may be located upstream or downstream of transcription start site. Each enhancer is made up of short DNA sequences called distal control elements<\/strong> . <\/span><\/p>\n Proteins called Activators\u00a0 , mediator proteins and transcription factors <\/strong>bind to the enhancers .When a transcription factor binds to its enhancer sequence, the shape of the\u00a0 transcription factor protein changes. This enables the transcription factor to\u00a0 \u00a0interact with proteins at the promoter site. <\/span><\/p>\n As the enhancer region may be distant from the promoter, the DNA must bend to allow the proteins at the two sites to come into contact. DNA bending proteins help to bend the DNA and bring the enhancer and promoter regions together.<\/span><\/p>\n \u00a0Two different genes may have the same promoter but different distal control elements, enabling differential gene expression.<\/span><\/p>\n “Enhancers” image<\/a> from Biology<\/em>, an OpenStax resource <\/a>is licensed under\u00a0CC BY 4.0<\/a><\/span><\/p>\n \u00a0The TATA box :<\/strong> This resembles the the -10 sequence element of bacterial promoters. This region contain the sequence TATAA\u00a0 and is located 25 to 30 nucleotides upstream of the transcription start site. <\/span><\/p>\n Initiator, or Inr, sequence : <\/strong>In addition to the TATA box ,<\/span> the promoters of many gene contain a second important sequence element called initiator, or Inr, sequence. Some RNA polymerase II promoters contain only an Inr element, with no TATA box.\u00a0<\/span><\/p>\n The promoter -proximal elements : The CAAT box<\/strong>, with the consensus sequence 5\u2019-CCAAT-3\u2019<\/strong> and the GC box,<\/strong> with the consensus sequence 5\u2019-GGGCGG-3\u2019. <\/strong>These\u00a0 promoter-proximal elements\u00a0 regulate gene transcription.<\/p>\n “Eukaryotic Transcription Initiation” image from the book General Biology (Boundless) <\/a>licensed under\u00a0CC BY-SA 4.0<\/a><\/span><\/p>\n These are binding sequences for transcription factors and may be located upstream or down stream of transcription start site <\/p>\n<\/div>\r\n \t
Enhancers<\/h1>\r\n
![\"Figure](\"http:\/\/pressbooks.justwrite.in\/understanding-gene-regulation\/wp-content\/uploads\/sites\/17\/2023\/03\/Enhancer.jpg\")
\r\nThe promoters of RNA polymerase II<\/h1>\r\n
Initiation-Formation of the Transcription complex <\/span><\/h1>\r\n
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![\"Transcription](\"http:\/\/pressbooks.justwrite.in\/understanding-gene-regulation\/wp-content\/uploads\/sites\/17\/2023\/03\/Tanscritio-complex-assembly-and-binding-RNA-polymerase-II.jpeg\")
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Transcription Factors<\/h1>\n
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Enhancers<\/h1>\n
<\/p>\nThe promoters of RNA polymerase II<\/h1>\n
Initiation-Formation of the Transcription complex <\/span><\/h1>\n
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