Alternative Ribosome-rescue Factor A

	Alternative Ribosome-rescue Factor A Alternative ribosome-rescue factor A (ArfA, YhdL) also known as peptidyl-tRNA hydrolase, is a protein that plays a role in rescuing of stalled ribosomes. It recruits RF2. See also * ArfB - Alternative ribosome-rescue factor B References {{Reflist Proteins ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu]
picture info	Stalled Ribosome Ribosomal pause refers to the queueing or stacking of ribosomes during translation of the nucleotide sequence of mRNA transcripts. These transcripts are decoded and converted into an amino acid sequence during protein synthesis by ribosomes. Due to the pause sites of some mRNA's, there is a disturbance caused in translation. Ribosomal pausing occurs in both eukaryotes and prokaryotes. A more severe pause is known as a ribosomal stall. It's been known since the 1980s that different mRNAs are translated at different rates. The main reason for these differences was thought to be the concentration of varieties of rare tRNAs limiting the rate at which some transcripts could be decoded. However, with research techniques such as ribosome profiling, it was found that at certain sites there were higher concentrations of ribosomes than average, and these pause sites were tested with specific codons. No link was found between the occupancy of specific codons and amount of their tRNAs. Thus ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu]
	Release Factor A release factor is a protein that allows for the termination of translation by recognizing the termination codon or stop codon in an mRNA sequence. They are named so because they release new peptides from the ribosome. Background During translation of mRNA, most codons are recognized by "charged" tRNA molecules, called aminoacyl-tRNAs because they are adhered to specific amino acids corresponding to each tRNA's anticodon. In the standard genetic code, there are three mRNA stop codons: UAG ("amber"), UAA ("ochre"), and UGA ("opal" or "umber"). Although these stop codons are triplets just like ordinary codons, they are not decoded by tRNAs. It was discovered by Mario Capecchi in 1967 that, instead, tRNAs do not ordinarily recognize stop codons at all, and that what he named "release factor" was not a tRNA molecule but a protein. Later, it was demonstrated that different release factors recognize different stop codons. Classification There are two classes of release factor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu]
	Alternative Ribosome-rescue Factor B Alternative ribosome-rescue factor B (ArfB, YaeJ) also known as peptidyl-tRNA hydrolase, is a protein that plays a role in rescuing of stalled ribosomes. It works like a GGQ-release factor itself, releasing the peptide from tRNA. At the same time, it fits into the mRNA tunnel to remove the mRNA. This gene is also found in eukaryotic organelles as MRPL58 (ICT1). The similarity is high enough to be interchangeable. Its role has expanded to that of a codon-independent release factor, although it likely still functions in ribosomal rescue. See also * ArfA - Alternative ribosome-rescue factor A Alternative ribosome-rescue factor A (ArfA, YhdL) also known as peptidyl-tRNA hydrolase, is a protein that plays a role in rescuing of stalled ribosomes. It recruits RF2. See also * ArfB - Alternative ribosome-rescue factor B References ... References {{Reflist Proteins ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu]