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What is the end result of DNA transcription?

The outcome of Transcription is a complimentary strand of messengerRNA (mRNA).

Is DNA changed during transcription?

Transcription, however, differs from DNA replication in several crucial ways. Unlike a newly formed DNA strand, the RNA strand does not remain hydrogen-bonded to the DNA template strand. Instead, just behind the region where the ribonucleotides are being added, the RNA chain is displaced and the DNA helix re-forms.

What happens after transcription?

After transcription the RNA molecule is processed in a number of ways: introns are removed and the exons are spliced together to form a mature mRNA molecule consisting of a single protein-coding sequence. RNA synthesis involves the normal base pairing rules, but the base thymine is replaced with the base uracil.

What is removed from mRNA during processing?

The process of removing introns and reconnecting exons is called splicing. Introns are removed and degraded while the pre-mRNA is still in the nucleus. Splicing occurs by a sequence-specific mechanism that ensures introns will be removed and exons rejoined with the accuracy and precision of a single nucleotide.

What is the purpose of 5 cap and poly A tail?

The 5′ cap protects the nascent mRNA from degradation and assists in ribosome binding during translation. A poly (A) tail is added to the 3′ end of the pre-mRNA once elongation is complete.

Why is a poly-A tail added to mRNA?

The poly-A tail is a long chain of adenine nucleotides that is added to a messenger RNA (mRNA) molecule during RNA processing to increase the stability of the molecule. The poly-A tail makes the RNA molecule more stable and prevents its degradation. …

Why do histone mRNA lack poly-A tail?

The metazoan replication-dependent histone mRNAs are unusual as they are the only eukaryotic mRNAs that lack poly(A) tails. Typically the replication-dependent histone mRNAs lack introns, and their genes are arranged in clusters. A small number of histone proteins like H3. 3, H2a.

Which RNA does not have poly A tail?

These non-polyadenylated transcripts (poly(A)- RNAs) include ribosomal RNAs (rRNAs) generated by RNA polymerase I and III, other small RNAs generated by RNA polymerase III, and replication-dependent histone mRNAs [7] and a few recently described long non-coding RNAs (lncRNAs) [8, 9] synthesized by RNA polymerase II.

Are histones Polyadenylated?

The metazoan replication-dependent histone mRNAs are not polyadenylated but end instead in a conserved stem-loop, while in plants, and most single-cell eukaryotes, the replication-dependent histone mRNAs are polyadenylated [1].

What is non-Polyadenylated?

Non-polyadenylated (poly(A)−/ribo−) RNAs were enriched from total RNAs by removal of poly(A)+ RNA transcripts and ribosomal RNAs. Polyadenylated (poly(A)−/ribo−) RNAs were enriched from total RNAs with oligo(dT) selection.