| Rna Polymerase I |
Article Index for Rna Polymerase |
Articles about Rna Polymerase I |
Website Links For Rna |
Information AboutRna Polymerase I |
| CATEGORIES ABOUT RNA POLYMERASE I | |
| ec 2.7.7 | |
| dna replication | |
| proteins | |
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The process of transcription by Pol I is relatively unregulated ( RRNA for Ribosomes is always needed in large quantities). Correspondingly it undergoes a simple process of transcription, with few stages to be regulated. In the process of Transcription (by any polymerase) there are three main stages: #Initiation; requiring construction of the RNA polymerase complex on the gene's Promoter . #Elongation; the writing of the RNA transcript. #Termination; the finishing of RNA writing and dissasembly of the RNA polymerase complex. RNAP I INITIATION Initiation: the construction of the polymerase complex on the promoter. RNAP I requires no TATA Box in the promoter, instead relying on an UCS (Upstream '''C'''ontrol '''S'''equence). #UBF (Upstream '''B'''inding '''F'''actor) binds the UCS. #UCS recruits and binds a protein complex incorporating TBP (TATA '''B'''inding '''P'''rotein) and three TAFs (TBP '''A'''ssociated '''F'''actors) called SL1. The TBP is forced to bind non-sequence specifically. #Rrn3/TIFIA gets phosphorylated and binds RNAP I #RNAP I binds to the UBF/SL1 complex via Rrn3/TIFIA, and transcription starts. |
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