Term
| the products of RNA polymerase II action |
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Definition
| pre-mRNA molecules (the primary transcripts) |
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Term
| what happens to nearly all mRNA precursors in higher eukaryotes? |
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Definition
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Term
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Definition
| encoding regions of genes that are kept after splicing |
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Term
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Definition
| noncoding regions of genes that are removed by splicing |
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Term
| depiction of the processing of eukaryotic pre-rRNA |
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Definition
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Term
| how eukaryotic pre-rRNA gets processed |
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Definition
1: extensive modification of certain sequences on the pre-rRNA, on both ribose and base components, directed by many small nucleolar ribonucleoproteins (snoRNPs)
2: the pre-rRNA is assembled with ribosomal proteins in a large ribonucleoprotein
3: cleavage of modified pre-rRNA |
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Term
| small nucleolar ribonucleoproteins (snoRNPs) |
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Definition
direct the modification of certain sequences on the pre-rRNA, both on the ribose and base components
each of these proteins consists of 1 small nucleolar RNA (snoRNA) and several proteins |
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Term
| where more of the modification of pre-rRNA takes place |
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Definition
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Term
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Definition
| cleaves nucleotides from the 5' end of the tRNA precursor |
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Term
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Definition
| cleaves nucleotides from the 3' end of the tRNA precursor |
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Term
| tRNA nucleotidyltransferase |
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Definition
| adds CCA to the tRNA precursor |
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Term
| depiction of transfer RNA precursor processing |
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Definition
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Term
| what endonuclease does to tRNA precursor |
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Definition
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Term
| the most extensively modified transcription product |
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Definition
| that of RNA polymerase II |
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Term
| what happens to most of the transcription product of RNA polymerase II? |
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Definition
| most of it gets processed to mRNA |
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Term
| how the 5' end of the nascent RNA strand is modified shortly after the initiation of RNA synthesis |
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Definition
1: phosphoryl group removed by hydrolysis by RNA triphosphatase
2: the diphosphate 5' end of the RNA attacks the α-phosphorus atom of a molecule of GTP to form an unusual 5'-5' triphosphate linkage, catalyzed by guanylyltransferase; this forms the 5' cap
3: the N-7 N atom of the terminal guanine is then methylated by RNA N-7 guanine methyltransferase, which uses S-adenosylmethionine as the methyl donor; this forms cap 0 |
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Term
| how the 5' cap is formed during RNA synthesis |
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Definition
| the diphosphate 5' end of the RNA attacks the α-phosphorus atom of a molecule of GTP to form an unusual 5'-5' triphosphate linkage, catalyzed by guanylyltransferase |
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Term
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Definition
| the N-7 N atom of the terminal guanine is then methylated by RNA N-7 guanine methyltransferase, which uses S-adenosylmethionine as the methyl donor |
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Term
| how 5' caps make mRNAs more stable |
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Definition
| by protecting their 5' ends from nucleases and phosphatases |
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Term
| how caps enhance translation |
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Definition
| they enhance translation by eukaryotic protein-synthesizing systems |
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Term
| depiction of capping the 5' end |
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Definition
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Term
| something most eukaryotic mRNAs have added to their 3' end after transcription |
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Definition
| a polyadenylate (poly(A)) tail |
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Term
| how is the final form of the 3' end of the pre-mRNA created? |
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Definition
| the 3' end of the pre-mRNA is generated by a complex that contains a specific endonuclease (the cleavage and polyadenylation specifity factor, CPSF) that recognizes the sequence AAUAAA |
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Term
| depiction of polyadenylation of a primary transcript |
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Definition
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Term
| possible roles of the poly (A) tail that is added to mRNA |
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Definition
-might enhance translation efficiency
-might make the mRNA more stable
-more effective template for protein synthesis |
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Term
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Definition
| the removal of introns and combining of exons to form the final product |
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Term
| this is required for accurate splicing of mRNA |
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Definition
| clear marking of correct splice sites |
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Term
| common structural motif of splice sites in eukaryotes |
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Definition
| the intron begins with GU and ends with AG |
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Term
| depiction of the transcription and translation of the β-globin gene |
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Definition
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Term
| depiction of splice sites |
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Definition
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Term
| what are the molecular machines that so precisely excise introns and join exons? |
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Definition
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Term
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Definition
| large splicing complex formed by a group of special RNAs and more than 300 proteins that combine with pre-mRNA |
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Term
| small nuclear RNAs (snRNAs) |
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Definition
| class of RNAs that is essential in the spliceosome |
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Term
| small nuclear ribonucleoprotein particles (snRNPs) (pronounced "snurps") |
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Definition
| RNA-protein complexes that are composed of small nuclear RNAs (snRNAs) and their associated proteins |
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Term
| depiction of spliceosome assembly and action |
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Definition
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Term
| what forms the catalytic center of the spliceosome? |
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Definition
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Term
| depiction of the splicing catalytic center |
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Definition
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Term
| 2 noteworthy features of the splicing process |
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Definition
1: RNA molecules play key roles in directing the alignment of splice sites and in carrying out catalysis
2: ATP-powered helicases unwind RNA duplex intermediates that facilitate catalysis and induce the release of snRNPs from the mRNA |
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Term
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Definition
| rxn of an alcohol with an ester to form a different alcohol and a different ester |
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Term
| mRNA transcription and processing seem to be coordinated by... |
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Definition
| the carboxyl-terminal domain (CTD) of RNA polymerase II |
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Term
| how the carboxyl-terminal domain (CTD) of RNA polymerase II contributes to efficient transcription |
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Definition
| by recruiting proteins to the pre-mRNA |
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Term
| depiction of the CTD: coupling transcription to pre-mRNA processing |
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Definition
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Term
| proteins recruited by the carboxyl-terminal domain (CTD) of RNA polymerase II |
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Definition
-capping enzymes
-components of the splicing machinery
-an endonuclease that cleaves the transcript at the poly(A) addition site |
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Term
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Definition
| methylate the 5' guanine on the pre-mRNA immediately after transcription begins |
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Term
| what endonuclease does to the pre-mRNA |
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Definition
| cleaves it at the poly(A) addition site, creating a free 3'-OH group that is the target for 3' adenylation |
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