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Definition
| family of introns all members of which fold into distinctive phylogenetically conserved secondary structures (catalytic core) consisting of 10 paired segments, few hundred nucleotides to 3000, lacks P1 helix that contains substrate for first splicing reaction |
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Term
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Definition
| smallest known RNA catalyst specified by virus-like RNA molecules that infect plants, cleaves specific phosphodiester bond within itself, looks like hammerhead, conserved junction sequence, constructed from two separate RNAs, one = catalyst, one = substrate |
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Definition
| spacer that separates rRNA coding regions, has promoter and transcription terminator for transcription units |
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Definition
| well-defined transcription and processing "factory" within the nucleus that contains active rRNA transcription units and RNA polymerase I transcription machinery, no membrane, |
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Term
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Definition
| entral component of the ribosome, the protein manufacturing machinery of all living cells, provide a mechanism for decoding mRNA into amino acids and to interact with the tRNAs during translation by providing peptidyl transferase activity |
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Definition
| enzyme responsible for synthesizing pre-rRNA in eukaryotes, transcribes rRNA gene clusters |
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Definition
| recognizes three different types of promoters, requires different transcription factors for transcription from 5S rRNA promoters and tRNA promoters |
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Term
| small nucleolar RNA (snoRNA) |
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Definition
| RNA molecules present in the nucleolus that serve as guides that identify target nucleotides within rRNA |
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Term
| small ribonucleoprotein (snoRNP) |
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Definition
| complexes present in the nucleolus that contain snoRNA and enzymes needed for methylation or pseudouridylation |
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