Protein Synthesis -Translation and Regulation
Drag-and-Drop Protein Synthesis: Quiz - zeroBio
The best known and studied bacterial toxin is the diphtheria toxin,produced by . Diphtheria toxin is abacterialexotoxin of the A/B prototype. It is produced as single polypeptidechainwith a molecular weight of 60,000 daltons. The function of the proteinis distinguishable into two parts: subunit A, with a m.w. of 21,000daltons,contains the enzymatic activity for inhibition of elongation factor-2involvedin host protein synthesis; subunit B, with a m.w. of 39,000 daltons, isresponsible for binding to the membrane of a susceptible host cell. TheB subunit possesses a region T (translocation) domain which insertsinto the endosome membrane thus securing the release of the enzymaticcomponent into the cytoplasm.
PROTEIN Synthesis | Translation (Biology) | Rna
The three codons, UAA known as ochre, UAG as amber and UGA as opal, that do not code for an amino acid but act as signals for the termination of protein synthesis.
A regulatory protein that binds to DNA and affects transcription of specific genes.
Roles of Protein Synthesis Elongation Factor EF-Tu in …
In the elongation stage of translation, amino acids are added one by one to the preceding amino acid.
The anticodon of an incoming aminoacl tRNA base-pairswith the complementary mRNA codon in the A site.
Peptide Bond Formation
An rRNA molecule of the large ribosomal subunit catalyzes the formation of a peptide bond between the new amino acid in the A site and the carboxyl end of the growing polypeptide in the P site.
The ribosome translocates the tRNA in the A site to the P site.
Protein synthesis elongation ..
There are a variety of ways that toxin subunits may be synthesizedandarranged: A + B indicates that the toxin is synthesized andsecretedas two separate protein subunits that interact at the target cellsurface;A-Bor A-5B indicates that the A and B subunits are synthesizedseparately,but associated by noncovalent bonds during secretion and binding totheirtarget; 5B indicates that the binding domain of the protein iscomposedof 5 identical subunits. A/B denotes a toxin synthesized as asinglepolypeptide, divided into A and B domains that may be separated byproteolyticcleavage.