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Full-Text Articles in Physical Sciences and Mathematics
The Role Of Smpb In Licensing Tmrna Entry Into Stalled Ribosomes, Mickey R. Miller
The Role Of Smpb In Licensing Tmrna Entry Into Stalled Ribosomes, Mickey R. Miller
Theses and Dissertations
Ribosomes translate the genetic information contained in mRNAs into protein by linking together amino acids with the help of aminoacyl-tRNAs. In bacteria, protein synthesis stalls when the ribosome reaches the 3'-end of truncated mRNA transcripts lacking a stop codon. Trans-translation is a conserved bacterial quality control process that rescues stalled ribosomes. Transfer-messenger RNA (tmRNA) and its protein partner SmpB mimic a tRNA by entering the A site of the ribosome and accepting the growing peptide chain. The ribosome releases the truncated mRNA and resumes translation on the tmRNA template. The open reading frame found on tmRNA encodes a peptide tag …
Ribosomal Rna Mutations That Inhibit The Activity Of Transfer-Messenger Rna Of Stalled Ribosomes, Jacob N. Crandall
Ribosomal Rna Mutations That Inhibit The Activity Of Transfer-Messenger Rna Of Stalled Ribosomes, Jacob N. Crandall
Theses and Dissertations
In eubacteria, stalled ribosomes are rescued by a conserved quality-control mechanism involving transfer-messenger RNA (tmRNA) and its protein partner SmpB. Mimicking a tRNA, tmRNA enters stalled ribosomes, adds Ala to the nascent polypeptide, and serves as a template to encode a short peptide that tags the nascent protein for destruction. To further characterize the tagging process, we developed two genetic selections that link tmRNA activity to cell death. These negative selections can be used to identify inhibitors of tagging or to identify mutations in key residues essential for ribosome rescue. Little is known about which ribosomal elements are specifically required …
The Role Of Smpb In The Early Stages Of Trans-Translation, Deanna June Cazier
The Role Of Smpb In The Early Stages Of Trans-Translation, Deanna June Cazier
Theses and Dissertations
Ribosomes stall on defective messenger RNA transcripts in eubacteria. Without a mechanism to release stalled ribosomes, these cells would die. Transfer-messenger RNA (tmRNA) and small protein B (SmpB) reactivate stalled ribosomes in a process known as trans-translation. Together, tmRNA and SmpB mimic alanyl-tRNA, entering the A site of stalled ribosomes and accepting transfer of the stalled polypeptide. A portion of tmRNA is then positioned as a template for the ribosome to resume translating. The tmRNA open reading frame encodes a proteolysis tag to mark the aberrant polypeptide for degradation and a stop codon to release the ribosome. How are tmRNA …
Genetic Analysis Of The Role Of Smpb In Establishing The Reading Frame On Tmrna, Talina Christensen Watts
Genetic Analysis Of The Role Of Smpb In Establishing The Reading Frame On Tmrna, Talina Christensen Watts
Theses and Dissertations
Ribosomes translate the genetic information encoded by mRNA into proteins. Defective mRNAs can cause stalling of translating ribosomes. The molecule tmRNA (transfer-messenger RNA) rescues stalled ribosomes in eubacteria. Together with its protein partner SmpB, tmRNA mimics a tRNA by entering the ribosomal A site and linking an alanine residue to the growing polypeptide chain. The ribosome then abandons the defective mRNA template and resumes translation on tmRNA, adding ten more amino acids to the nascent polypeptide. As a result of tmRNA action, stalled ribosomes are released and recycled, the defective mRNA is destroyed, and the aborted protein product is tagged …