Genetik 2_RNA Transcription and Processing

Genetik 2_RNA Transcription and Processing

Genetik 2_RNA Transcription and Processing


M. K.
This flashcard set delves into the intricate processes of RNA transcription and processing at the university level, focusing on key concepts like RNA synthesis, gene expression, and the roles of molecules such as polymerase, DNA, and proteins. It covers the stages of transcription, including initiation, elongation, and termination, as well as RNA processing events like splicing and the formation of transcripts. Ideal for biology students and researchers, this flashcard set provides a comprehensive overview of the molecular mechanisms underlying gene expression and RNA function, offering insights into how genetic information is transcribed and processed within organisms.
Karten
62
Lernende
1
Sprache
Englisch
Kategorie
Biologie
Stufe
Universität
Erstellt / Aktualisiert
04.01.2017 / 05.01.2017

Lernkarten

antisense RNA strand

An RNA strand having a sequence complementary to a transcribed strand.

cap

A special structure, consisting of a 7-methylguanosine residue linked to the transcript by three phosphate groups, that is added in the nucleus to the 5' end of eukaryotic mRNA. The cap protects an mRNA from degradation and is required for translation of the mRNA in the cytoplasm.

carboxy terminal domain

CTD. The protein tail of the Beta subunit of RNA polymerase II. It coordinates the processing of eukaryotic pre-mRNA including capping, splicing, and termination.

coding strand

The nontemplate strand of DNA molecule having the same sequence as that in the RNA transcript.

consensus sequence

The nucleotide sequence of a segment of DNA that is in agreement with most sequence reads of the same segment from different individuals.

constitutive heterochromatin

Chromosomal regions of permanently condensed chromatin usually around the telomeres and centromeres.

cosuppression

An epigenetic phenomenon whereby a transgene becomes reversibly inactivated along with the gene copy in the chromosome.

cotranscriptional processing

The simultaneous transcription and processing of eukaryotic pre-mRNA.

dicer

A protein complex that recognizes long double-stranded RNA molecules and cleaves them into double-stranded siRNAs. Dicer plays a key role in RNA interference.

double-stranded RNA

dsRNA, An RNA molecule comprised of 2 complementary strands

downstream

A way to describe the relative location of a site in a DNA or RNA molecule. A downstream site is located closer to the 3' end of a transcription unit.

elongation

The stage of transcription that follows initiation and precedes termination.

endogenous gene

A gene that is normally present in an organism, in contrast with foreign gene from a different organism that might be introduced by transgenic techniques.

exon

Any nonintron section of the coding sequence of a gene, together, the exons correspond to the mRNA that is translated into protein.

functional RNA

An RNA type that plays a role without being translated.

gene expression

The process by which a gene's DNA sequence is transcribed into RNA and, for protein-coding genes, into polypeptide.

general transcription factor

GTF. A eukaryotic protein complex that doesnt take part in RNA synthesis but binds to the promoter region to attract and correctly position RNA polymerase II for transcription initiation.

gene silencing

A gene that is not expressed owing to epigenetic regulation. Unlike genes that are mutant due to DNA sequence alterations, genes inactivated by silencing can be reactivated.

genetically modified organism (GMO)

A popular term for a transgenic organism, especially applied to transgenic agricultural organisms.

GU-AG rule

So named because the GU and AG dinucleotides are almost always at the 5' and 3' ends, respectively, of introns, where they are recognized by components of the spliceosome.

initiation

The first stage of transcription or translation. Its main function in transcription is to correctly position RNA polymerase before the elongation stage, and in translation it is to correctly position the first aminoacyl-tRNA in the P site.

intron

A segment of largely unknown function within a gene. This segment is initially transcribed, but the transcript is not found in the functional mRNA.

long nonconding RNAs

lncRNA. Nonprotein-coding transcripts that are over 200 nucleotides in length.

messenger RNA

mRNA. An RNA molecule transcribed from the DNA of a gene. A protein is translated from this RNA molecule by the action of ribosomes.

microRNA

miRNA. A class of functional RNA that regulates the amount of protein produced by a eukaryotic gene.

non-protein-coding RNA

ncRNA. RNA that is not translated into protein.

piwi-interacting RNA

piRNA. An RNA transcribed from pi-clusters that helps to protect the integrity of plant and animal genomes and to prevent the spread of transposable elements to other chromosomal loci. piRNAs restrain transposable elements in animals

poly(A) tail

A string of adenine nucleotides added to mRNA after transcription.

post-transcriptional processing

modifications of AS side groups after a protein has been translated.

preinitiation complex

PIC. A very large eukaryotic protein complex comprising RNA polymerase II and the six general transcription factors (GTFs), each of which is a multiprotein complex.

primary transcript

pre-mRNA. Eukaryotic RNA before it has been processed.

promoter

A regulation region that is a short distance from the 5' end of a gene and acts as the binding site for RNA polymerase.

proteome

The complete set of the protein-coding genes in the genome.

pulse-chase experiment

An experiment in which cells are grown in radioactive medium for a brief period (the pulse) and then transferred to nonradioactive medium for a longer period (the chase).

ribose

The pentose sugar of RNA

ribosomal RNA

rRNA. A class of RNA molecules, encoded in the nucleolar organizer, that have an integral role in ribosome structure and function.

ribozyme

An RNA with enzymatic activity - for instance, the self-splicing RNA molecules in Tetrahymena.

RISC (RNA-induced silencing complex)

A multisubunit protein complex that associates with siRNAs and is guided to a target mRNA by base complementary. The target mRNA is cleaved by RISC activity.

RNA interference

RNAi. A system in eukaryotes to control the expression of genes through the action of siRNAs and miRNAs. (gene silencing)

RNA polymerase

An enzyme that catalyzes the synthesis of an RNA strand from a DNA template. Eukaryotes possess several classes of RNA polymerase: structural genes encoding proteins are transcribed by RNA polymerase II.

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