Which one of the following steps in prokaryotic translation does NOT require hydrolysis of GTP? Initiation factor IF2 is bound to GTP at this step, but hydrolysis does not occur until later.
Which one of the following steps in translation does not require hydrolysis of GTP?
Which one of the following steps in prokaryotic translation does NOT require hydrolysis of GTP? Initiation factor IF2 is bound to GTP at this step, but hydrolysis does not occur until later.
Which process in translation requires GTP hydrolysis?
The requirement for hydrolysis of GTP before EF-Tu or eEF-1α is released from the ribosome is the rate-limiting step in elongation and provides a time interval during which an incorrect aminoacyl tRNA, which would bind less strongly to the mRNA codon, can dissociate from the ribosome rather than being used for protein ...
Which step in protein synthesis does not require GTP?
GTP is not hydrolyzed until aminoacyl-tRNA is delivered to the A site of the ribosome. An earlier hydrolysis of GTP would be wasteful because EF-Tu-GDP has little affinity for aminoacyl-tRNA.
Which of the following stages of translation does not require energy in the form of GTP?
The next incoming tRNA is called amino acyl tRNA, it is bound to A-site. A peptide bond is formed between COOH group of the t-RNA at P-site and NH, group of aminoacyl t-RNA. This is facilitated by the enzyme peptidyl transferase and does not require high energy phosphate bonds.
How is protein synthesis terminated?
Protein synthesis is terminated by the elongating ribo – some upon its arrival at one of the three stop codons – UAA, UAG or UGA – at the decoding site. In the absence of a tRNA able to efficiently decode the stop codon, a protein release factor (RF) binds to the ribo- some.
What event occurs during translocation?
A translocation occurs when a piece of one chromosome breaks off and attaches to another chromosome . This type of rearrangement is described as balanced if no genetic material is gained or lost in the cell. If there is a gain or loss of genetic material, the translocation is described as unbalanced .
What is the function of GTP in translation?
During the elongation stage of translation, GTP is used as an energy source for the binding of a new amino-bound tRNA to the A site of the ribosome . GTP is also used as an energy source for the translocation of the ribosome towards the 3′ end of the mRNA.
Is GTP hydrolysis required for translation?
The translocation of tRNA and mRNA through the ribosome is promoted by elongation factor G (EF-G), a GTPase that hydrolyzes GTP during the reaction. ... GTP hydrolysis is required for rapid tRNA–mRNA movement , and P i release induces further rearrangements of both EF-G and the ribosome that are required for EF-G turnover.
What happens when GTP is hydrolyzed?
The GTP-bound conformation is biologically active and promotes a cellular function, such as signal transduction, cytoskeleton organization, protein synthesis/translocation, or a membrane budding/fusion event. GTP hydrolysis turns off the GTPase switch by converting it to the inactive GDP-bound conformation .
What are the 7 steps of protein synthesis?
- DNA unzips in the nucleus.
- mRNA nucleotides transcribe the complementary DNA message.
- mRNA leaves nucleus and goes to ribosome.
- mRNA attaches to ribosome and first codon is read.
- tRNA brings in proper amino acid from cytoplasm.
- a second tRNA brings in new amino acid.
What are the 4 steps of protein synthesis?
- Initiation is the beginning of transcription. It occurs when the enzyme RNA polymerase binds to a region of a gene called the promoter. ...
- Elongation is the addition of nucleotides to the mRNA strand.
- Termination is the ending of transcription. The mRNA strand is complete, and it detaches from DNA.
What are the six steps of protein synthesis?
Terms in this set (6)
The messenger molecule (mRNA) is fed through the ribosome 3 bases at a time . Transfer molecules called tRNA bring the correct AA (amino acid) from the cytoplasm to the ribosome. Transfer molecules (tRNA) drop amino acids (AA) off at the ribosome.
What are the 4 steps of translation?
Translation happens in four stages: activation (make ready), initiation (start), elongation (make longer) and termination (stop) . These terms describe the growth of the amino acid chain (polypeptide). Amino acids are brought to ribosomes and assembled into proteins.
Is IF2 a GTPase?
IF2 is a GTPase that functions to position the initiator tRNA within the 30S ribosomal initiation complex (30S IC) and promotes its joining with the 50S ribosomal subunit to form a 70S ribosome. IF2 is encoded by a single copy of the infB gene and is completely conserved in bacteria (1).
What does translation end with?
Translation ends in a process called termination . Termination happens when a stop codon in the mRNA (UAA, UAG, or UGA) enters the A site. Stop codons are recognized by proteins called release factors, which fit neatly into the P site (though they aren’t tRNAs).
