From messenger RNA to a protein chain

Next, the ribosome moves along the messenger RNA chain to the next codon. At the same time a peptide bond is made between the two amino acids, and the first one (the methionine) breaks away from its transfer RNA.

TRANSCRIPTION - FROM DNA TO RNA

Finding the start point of the messenger RNA

How does messenger RNA differ from DNA?

Mildenhall KB, Wiese N, Chung D, et al. (2016) RNase E‐based degradosome modulates polyadenylation of mRNAs after Rho‐independent transcription terminators in Escherichia coli. Molecular Microbiology 101: 645–655.

Before we can talk about that we have to introduce transfer RNA . . .

Transcription is under the control of the enzyme . The first thing that the enzyme has to do is to find the start of the gene on the coding strand of the DNA. Remember that DNA has lots of genes strung out along the coding strand. That means that the enzyme has to pick the right strand and identify the beginning of each gene.

T1 - β-Actin messenger RNA localization and protein synthesis augment cell motility

20/12/2017 · The synthesis of mes..

And again, the ribosome moves forward one codon, a new peptide bond is formed, and the transfer RNA on the left breaks away to be used again later.

Protein Synthesis Process and Role of DNA And RNA In It

In DNA the hydrogen bonding between A and T helps to tie the two strands together into the double helix. That isn't relevant in RNA because it is only a single strand. However, you will find several examples in what follows on this and further pages where the ability of adenine (A) to attract and bond with uracil (U) is central to the processes going on.

Protein Synthesis Process and Role of DNA And RNA ..

As it was finally understood, several types of RNA represent a basic division of labor in protein synthesis. Messenger RNA (mRNA) presents information contained in DNA sequences to the ribosomes, which are structured by ribosomal RNA (rRNA). Other molecules, known as transfer RNA (tRNA), attach to specific amino acids and conduct them to the ribosomes for protein synthesis.

That transfer RNA molecule leaves the ribosome and goes off to pick up another methionine.

Structure and function of Messenger RNA (mRNA )


Frameshift mutations
insertion
deletion
Point Mutations
a single nucleotide (base) changes in the DNA or RNA

DNA
A-T
G-C
C-A
Frameshift Mutations
Insertion
A nucleotide is added to the DNA strand being created, causing a shift in all remaining nucleotides

Deletion
A nucleotide is removed from the DNA strand being created, causing a shift in all remaining nucleotides
Central Dogma
DNA codes for RNA
RNA guides the synthesis of proteins

RNA processing
In comparing DNA code with its transcribed mRNA code, scientists found that the mRNA code was much shorter.

DNA sequences not found in mRNA are called
introns
.

DNA sequences that remain in the final mRNA are called
exons
.

RNA Processing
mRNA code is significantly shorter than the DNA code
The DNA code is interrupted by sequences that are not in the final mRNA sequence known as
introns
.
the coding sequence that remain in the final mRNA are called
exons
.

During transcription, what does messenger RNA do?

Portier C, Dondon L, Grunberg‐Manago M and Regnier P (1987) The first step in the functional inactivation of the Escherichia coli polynucleotide phosphorylase messenger is ribonuclease III processing at the 5′ end. EMBO Journal 6: 2165–2170.

The synthesis of messenger RNA is called translation

Mizuno T, Chou MY and Inouye M (1984) A unique mechanism regulating gene expression: translational inhibition by a complementary RNA transcript (micRNA). Proceedings of the National Academy of Sciences of the United States of America 81: 1966–1970.