Questions tagged [translation]

Translation is the process of protein synthesis. The information encoded in the mRNA is translated into an amino acid sequence through the joint activity of tRNAs and ribosomes.

7
votes
2answers
1k views

Redundancy of the genetic code

One particular codon codes only for one amino acid, but an amino acid can be coded for by several different codons. Now according to the genetic code, the codon UUU ...
21
votes
2answers
10k views

Do all proteins start with methionine?

Start codon AUG also codes for methionine and without start codon translation does not happen. And even the ambiguous codon GUG codes for methionine when it is first. So does this mean that all ...
12
votes
3answers
2k views

How did the genetic code evolve?

The genetic code is redundant, there are 20 amino acids for 64 possible nucleotide combinations (triplet codons). Therefore some amino acid are coded by several different codons. While leucine is ...
7
votes
3answers
2k views

Why is an initiator tRNA required, distinct from the methionine tRNA used in elongation?

I'm confused by why there is a need for different tRNA-methionine complexes for translational initiation and elongation. This paper mentions that It is important that each type of methionyl tRNA ...
11
votes
4answers
12k views

Why is AUG the initiation codon?

Is there any reason why AUG is the initiation codon? Can’t translation start with different codons?
13
votes
2answers
365 views

Are codons that map to the same amino acids interchangeable?

From wikipedia, in the section on the RNA codon table, I see a mapping between codons and amino acids. There, Valine is related to GUU, GUA, GUG, GUC. Does it mean in the same context that these ...
6
votes
2answers
532 views

Can ribosomes read ssDNA?

My question is whether translation can be done, either naturally or artificially, through a ribosome reading (single-stranded) DNA directly. If not, I would like to know what allows ssRNA to be ...
24
votes
1answer
7k views

What is the criticality of the ribosome binding site relative to the start codon in prokaryotic translation?

In prokaryotic translation, how critical for efficient translation is the location of the ribosome binding site, relative to the start codon? Ideally, it is supposed to be -7b away from the start. ...
15
votes
2answers
6k views

How does translational coupling work in prokaryotes?

Today I heard about a phenomenon called "translational coupling", where the translation of one protein influences the translation of another protein. The messenger RNA levels don't seem influenced. ...
15
votes
1answer
779 views

Can DNA act as a translation substrate?

I get conflicting answers. One would think if it was true, it would be rather seminal and widely known. There are papers from Khorana[1], Holland[2], and Bretscher[3] (late 60s) that suggest that it ...
8
votes
1answer
8k views

The GUG start codon in E. coli: identity of initiating tRNA and efficiency of translation

Translation in E. coli is usually initiated at an AUG codon, which encodes the amino acid methionine. In some cases, however, the start codon is GUG, which normally encodes valine. If GUG is used as ...
7
votes
4answers
15k views

RNA or ribosome, which one moves during translation?

During translation ribosomes decode the genetic information present in the mRNA and protein synthesis takes place. During this process which of those two does move, the ribosome or the mRNA?
2
votes
3answers
4k views

Effect of a doubling of the start codon in a gene

I am learning about frameshift mutations. Frameshifts can occur due to a nucleotide deletion. Suppose that due to a frameshift, because of a deletion somewhere upstream from the original start codon, ...
2
votes
1answer
476 views

Translation of Poly-U in the Nirenberg and Matthaei experiment

In the Nirenberg and Matthaei experiment the artificial mRNA, polyU, was translated into polyphenylalanine in a cell-free system, establishing that UUU was the codon for Phe. How did this work as the ...
10
votes
1answer
1k views

How are there alternative initiation codons?

According to wikipedia and the original complete sequence of the K-12 genome, there are multiple non-AUG start codons such as GUG and UUG. How is this possible? I'm particularly curious about the ...
6
votes
3answers
5k views

Mutation That Loses Stop Codon

Someone asked this in my class and my instructor wasn't sure in her answer, doesn't anyone know what happens in protein synthesis if a mutation causes mRNA to not possess a stop codon? Would the ...
3
votes
2answers
1k views

Why does azithromycin not affect human mitochondria?

Drugs like tetracyclines, macrolides and aminoglycosides bind to prokaryotic ribosomes. It is interesting that our body too having mitochondria, which have prokaryotic ribosomes, there is little(?) ...
3
votes
1answer
4k views

ATP required for cell processes [closed]

I haven't been able to find anything that tells me how much ATP is needed for DNA replication, transcription, and translation in humans, just papers that mention ATP used in those processes. I need ...
3
votes
1answer
88 views

Why did translation develop a specific codon for initiation?

The translation of mRNA is initiated by a specific methionine-accepting tRNA at a specific initiation codon, usually AUG (complementary to the tRNA anticodon). However translation at suitable (albeit ...
2
votes
1answer
46 views

Relationship between the ambiguity (wobble) at codon position 3 in elongation and codon position 1 in initiation

In prokaryotes the usual observed start codon frequency is AUG > GUG > UUG. An explanation for this is that AUG is the most common initiator codon because it forms the most stable interaction with ...
2
votes
3answers
2k views

Relationship of the DNA of a eukaryotic gene to the 5'-UTR of its mRNA

In eukaryote pre-mRNA I am having a little trouble grasping exactly what the 5 prime untranslated region is defined as. It seems that it could be defined as the difference in pre-mRNA between the ...
1
vote
1answer
2k views

What type of mutation causes Progeria?

I'm doing my High School biology final on Progeria, and am wondering what type of mutation causes this disease. I know that the LMNA gene codes for the "prelamin A" protein, and that protein contains ...
0
votes
0answers
23 views

Production of ATP Synthase [duplicate]

I have been reading about the ubiquitous use of ATP as an energy source in biology. ATP Synthase is a very complicated protein enzyme. My question is, how could this protein have arisen. To form ...