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.

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Is there an Exit site (E-site) on the eukaryotic ribosome?

One of my professors mentioned something about the e-site (the exit site for the t-RNA) on a eukaryotic ribosome. There was a student in the class who objected, saying that there is no e-site on ...
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How does a ribosome move along mRNA?

I've been reading around Wikipedia recently trying to learn more about various biomechanisms. I’m intrigued by ribosomes — with how small they are, they’re basically chemical machines from what I can ...
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Could Wobble Base Pairing ultimately yield an amino acid that was originally uncalled for or not expected?

How does the cell choose which amino acid to attach to tRNA when there is wobble base pairing involved (not the other way around)? Consider the example below. For the purpose of this question I'm ...
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How much nucleoside triphosphate is required to form one peptide bond during protein synthesis?

I'm trying to find out how many molecules of nucleoside triphosphates (ATP, GTP, UTP and/or CTP) it takes to release enough energy to link two amino acid monomers together with a peptide bond, ...
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Can a ribosome attach to a RNA strand that is undergoing elongation by RNA polymerase, and concurrently start protein synthesize?

Is there any known mechanism (provide a concrete example) in which RNA translation can occur at the same time as DNA transcription, concerning a single RNA strand? In other words, can a ribosome ...
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Can mRNA be used by ribosomes more than once?

Can mRNA be used by ribosomes more than once? I mean can mRNA be translated more than one time? If not what will happen to it after translation?
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Are mitochondrial genes decoded in the same way as nuclear genes?

Mammalian mitochondrial genomes contain only 22 tRNA-coding genes, which is an insufficient number to decode mRNAs under the standard wobble rules. How is translation of mitochondrial mRNAs achieved ...
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Does every protein starts with Methionine amino acid [duplicate]

During process of protein synthesis we need AUG Codon to start translation .As we know this codon codes for Methionine amino acid so can we say that every protein starts with Methionine amino acid ?
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Why is AUG the initiation codon?

Is there any reason why AUG is the initiation codon? Can’t translation start with different codons?
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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 ...
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Why are there three stop codons but only one start codon?

I was wondering whether there is any specific reason that there are three stop codons but only one start codon in prokaryotic and eukaryotic cytoplasmic mRNAs.
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What is the frequency of AUG near-cognates (as start codon) in ‘Leaderless’ mRNA?

In typical bacteria that use SD-dependent translation initiation, the AUG start codon may sometimes be replaced by near-cognates (GUG, UUG, etc.). The frequency of these near-cognates is somewhat ...
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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 ...
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Why don't all protein sequences taken from DNA get synthesized?

Why don't all protein sequences in DNA get synthesized? The genome, and subsequently extracted proteome, is much larger than the collection of proteins for which there is any other experimental ...
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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 ...
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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 ...
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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 ...
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Do ribosomes read mRNA?

So I understand that tRNA bonds to a codon (with an anticodon) in the translation process. I read in my biology textbook that the ribosomes "read" the mRNA strand. Why do the ribosomes need to read ...
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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 ...
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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 ...
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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. ...
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About Frameshift Mutation

I am coding a DNA translater, based on the homosapiens genome, & i knowing that the data provided from NCBI is surely not 100% precise (there may be some base changes / removes etc...) , & i ...
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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 ...
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How to interpret the relationships of PTMs from BioGRID's data

On BioGRID Database, PTMREL is a file that describes relationships of the PTMs (Post Translation Modification) tabulated in a PTMTAB file. I have several issues with this file. Foremost, I am not ...
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Why do bacteria use formylated methionine in the initiator tRNA, while eukaryotes do not?

Could anyone suggest an explanation for the evolution of this trait in bacteria? Does it confer any advantage? It is also exploited by immunity receptors of some eukaryotes for the recognition of ...
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Is this sentence about RER correct on Wikipedia?

While studying about Endoplasmic Reticulum on Wikipedia, I came across this sentence A ribosome only binds to the RER once a specific protein-nucleic acid complex forms in the cytosol. This special ...
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Insertion of an additional base at start codon make the protein still functional?

So the question is if: a deletion of a codon for the amino acid lysine (AAG) is more or less likely to cause nonfunctionality of the protein than: Insertion of an additional base (C) within the ...
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Eukaryotic equivalent of bacterial tmRNA

According to this Wikipedia article, tmRNA is only found in bacteria, with its purpose being to “rescue stalled ribosomes”. This brings me to the question of is there a eukaryotic equivalent of this ...
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Do tRNAs that recognize multiple codons have any preference for one over another?

What are the effects of the different binding strength/affinity between the synonymous codons corresponding to a single tRNA ?
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How are mitochondrial ATT (Ile) start codons translated as Methionine?

In some vertebrate species, some mtDNA start codon sequences are ATT but these are translated as Methionine rather than Isoleucine. What is the mechanism for this non-standard translation? The main ...
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Why doesn’t a basic side chain (R group) of an amino acid form a peptide bond in protein biosynthesis? [closed]

Why doesn’t a basic side chain (R group) of an amino acid form a peptide bond in protein biosynthesis? Consider lysine, for example, why can’t its side-chain amino group, –(CH2)4–NH2, form a peptide ...
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Why is translation so much faster in prokaryotes than eukaryotes?

Prokaryotes perform transcription and translation much faster than eukaryotes. If memory serves, a single 70S prokaryotic ribosome can incorporate around 20 amino acids per second, whereas the 80S ...
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How is mRNA directed out of the nucleus to its ultimate cytoplasmic location?

In the process of translation, I learnt that following formation the mRNA must exit the nucleus through a nuclear pore and attach to a ribosome. My question is how does mRNA navigate itself out of ...
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Why Differential equation is not a good way to model chemical reaction networks [closed]

I'm a computer scientist and mostly code and have worked with Boolean models of cell level molecule transfer. Now i'm reading about the Biological pathways and modelling chemical reaction networks / ...
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History of ideas about the form of the genetic code

In preparing a lecture on mRNA translation and the genetic code, I remembered a talk given at a symposium where they mentioned the origin of the code and how, before the code was established, various ...
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Can one refer to pieces of proteins produced by enzymatic digestion as “enzymatic lysates”?

A Russian text I'm translating says this: The location of post-translational modification (PTM) sites was determined using the “bottom-up” approach commonly used in this field. In accordance with ...
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Does translation have a way of preventing mismatching between mRNA codons and tRNA anti-codons?

What happens in translation if a tRNA with an inappropriate (non-cognate) anti-codon binds to the A-site of the ribosome carrying mRNA? For example, what would happen if an ile tRNA with the anti-...
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How does aminoacyl-tRNA synthetase recognize different tRNAs?

There are about 20 aminoacyl-tRNA synthetases, one for each amino acid. Each aminoacyl-tRNA synthetase has a binding site that recognizes a specific amino acid, and other binding areas that recognize ...
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How do aminoacyl-tRNA synthases distinguish between similar amino acids?

How do aminoacyl tRNA synthases recognize the right amino acid for their tRNA? What is the structural reason behind the selective recognition? I have difficulty in seeing how, for example, leucine and ...
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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 ...
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Consensus sequence for selection of initiation codon in eukaryotes

In bacteria the AUG (or other) codon at which translation of mRNA is initiated is preceded at a precise distance by a sequence known as the Shine and Dalgarno sequence, to which the 30S subunit ...
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How does the tRNA recognise the first methionine during translation?

The process of translation starts with the initiator tRNA identifying the codon coding for methionine (AUG). However my textbook also says that there are various untranslated regions present on the ...
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What is the Shine–Dalgarno sequence?

I am trying to understand the Shine–Dalgarno sequence. I currently know it is related to ribosomal binding sites, it is only found in prokaryote cells and it is in front of the initial codon. Also, ...
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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, ...
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Is the start codon regarded as part of the UTR (untranslated region)?

The Wikipedia entry for Gene contains the statement: The transcribed pre-mRNA contains untranslated regions at both ends which contain a ribosome binding site, terminator and start and stop codons. ...
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Are there any examples in nature of two polypeptides joining into a single, continuous, third polypeptide?

Are there any examples in nature of two polypeptides join into a single, continuous, third polypeptide like this: (Where all the indicated amino and carboxyl groups are on the main polypeptide ...
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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 ...
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Division of proteins

This textbook states Proteins determined by a single gene may divide to form different proteins with various physiological actions. First how do proteins divide? Second if it's just fragmentation ...
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“producer cell line” vs. “host cell line” in biopharmacology

I'm translating a text that describes the creation and testing of a cell line that produces a drug (a protein) and also procedures for creation and maintenance of cell banks. Example sentence: ...
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Transport of newly synthesized proteins to cellular organelles

In the nucleus the DNA is transcribed and processed to mRNA which is translated into proteins in the cytoplasm. What happens between the time a protein is made and that when it reaches the cellular ...