What is the function of cap-binding protein?

What is the function of cap-binding protein?

eIF4E, the cap-binding protein promotes protein synthesis by binding to eIF4G. Beside its role in translation regulation, eIF4E is also important for mRNA stability and the proper subcellular localization of mRNA.

What is the function of a cap in transcription?

Capping occurs co-transcriptionally on the nascent pre-mRNA as it emerges from the RNA exit channel of RNA polymerase II. The cap structure protects mRNAs from degradation by exonucleases and promotes transcription, polyadenylation, splicing, and nuclear export of mRNA and U-rich, capped snRNAs.

What is the 5 cap of mRNA?

In eukaryotes, the 5′ cap (cap-0), found on the 5′ end of an mRNA molecule, consists of a guanine nucleotide connected to mRNA via an unusual 5′ to 5′ triphosphate linkage. This guanosine is methylated on the 7 position directly after capping in vivo by a methyltransferase.

What is a CAP in molecular biology?

The catabolite activator protein (CAP, also known as cAMP receptor protein, CRP) is a transcriptional activator, present as homodimer in solution, each subunit including a ligand-binding domain at the N-terminus and a DNA-binding domain at the C-terminus.

Is CAP a transcription factor?

The Escherichia coli catabolite activator protein (CAP; also known as the cAMP receptor protein, CRP) activates transcription at more than one hundred promoters.

What is a CAP binding site?

In these operons, a CAP-binding site is located upstream of the RNA-polymerase-binding site in the promoter. This increases the binding ability of RNA polymerase to the promoter region and the transcription of the genes.

What is the function of cap in RNA?

The mRNA cap is a highly methylated modification of the 5′ end of RNA pol II-transcribed RNA. It protects RNA from degradation, recruits complexes involved in RNA processing, export and translation initiation, and marks cellular mRNA as “self” to avoid recognition by the innate immune system.

What is the function of the 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.

Where does the CAP activator bind?

Catabolite activator protein (CAP) must bind to cAMP to activate transcription of the lac operon by RNA polymerase. CAP is a transcriptional activator with a ligand-binding domain at the N-terminus and a DNA -binding domain at the C-terminus.

How does CAP-cAMP work?

When glucose levels are low, cAMP is produced. The cAMP attaches to CAP, allowing it to bind DNA. CAP helps RNA polymerase bind to the promoter, resulting in high levels of transcription.

Does CAP bind promoter?

CAP-cAMP binds promoter DNA as a homodimer. CAP-cAMP assists RNA polymerase binding to the promoter by interacting with the carboxy-terminal domain of the alpha subunit of of RNA polymerase (alphaCTD), thereby enhnacing the frequency of transcription initiation of catabolic operons.

What is the function of CAP in RNA?

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