University:
Swansea University
Course:
PM-133 | Evolutionary and Molecular Genetics
Academic year:

2023
Views:

384

Pages:

7
Author:

Amal J.

Proofreading of synthetasediscinbase@ acceptercorrect tRNAaim2challenges of ERNAanticodon loopcorrect aa -structure1ERNALeu, synthetase should recognise 6 ERNALEU(inocapetingERNA) acceptor arm discriminator bases }checkedanticodonloopfor correcttRNAcorrect aa- selectionaa shape & structure sizestructuresome aa are dose in structureeg :- Phef tyreOHno OHtyr tRNA synthetase checks, forOltin tyr(y)ile & valone CH2bigsmallextra.synthetosechecksthis.val tRNA synthetase cannot hold elebutits basbi etetRNA has big pocketifactenglatedvaline attachescatalyticpocketIf flips to editing pocketnearex trapocketcatalyticvalampCPeditE.P ValayVal + AMPbreaked. hydrophobic aa synthetase (vice vasa in hydrophilic)aplined with hydrophotic aaE.P(Chydrophilichydrophilic aa synthetaseCPhydrophilic (repell hydeophobicad)EPhydeophobicIntiation (inr)Prokbinding of MRNA to ribosome & attachement oftRNA.both mRNA & ERNA has equal dhance to bind riboxfirst305 small165MRNAsobusit.antishine dalgaino - shine dalgardfinding](168)(mRNA)3' UCC UCC5AGGG 5' AGG AGG 3'5'IAGGAGG3,3'occuresProperpositioning and complemplace the ribosonce in correct position RBSPositioning of start codon @ PALGE^30sunitInprok normal AUG864.83%GUG - 14%startGUGUUG20%mostpreferableamong th2.UOG - 3/AUGAUU - 2genes onlyGUGformylated methionineDUUGJps tRNAIt should enter Prite3 consiativeG-C pair @ anticodosloop3'A5'CCC AG- Cunpaired - carey form-meth.C- G aminoacylaccepterarmADloopTloopG-CG_C3consicutiveG- CG-C- to place at P(UAC UALCAU anticodonAUG changing of f-metHearthH HI+N- C - cooJpr tRNA + metH3HCH2modificationCH2 methioninewith formylgrocipformylSIgroup(aCH3L -aninogroopIntiation factorsHtransformylaseN-- cooH-l3IF's0It CH2 FormylIF1IF2.IF3.FormlyCH2methioninegroup.GTPaseSbindcapacity.bind to1AsiteandE site ofCH3IF2 + GTPpreventsmall sobunitacitiveonablock theirentryIF2 - -GTPreasociation withofInt+tRNAIF 1larger subosit & blockon AE site,so Inr. +RNA correctly binds Psitesitefacilitatebinding ofGTPIF2Inr tRNAto1F3F1Prite .EPAformyl met enter. binding inducefmetconfir matiardGTP changEfree&F 3large unit copbirdrelease (dueloconfirmation change Unlinane activitieVIIIIIfactor Binding Site (FBS)Induce intrinsiclargeenters.aGTPase activity(GAPactivity)FBS + If2 - GTPIF2 GDPleavesEmalywith IFIFBSGTPEPAforIF2GDP+leaves191EPA70spreintiationcomplexElongationBinding of amino acyl tRNA to A sitePeptide bond formationtranslocation EFTOut GTP GTPase protein)EFTu GTPrecruite aa with ERNA toEFTUGTP+ ERNA9CThide bond b/w aa & (RNAacyl bond - energyunstable bondwhich can be easilybroken in pcytoplasm.forgetaaFBS + EFTU - GTPEFTU-GGTPleavesEPAGriphydiolysis reason-fidelity -EFTSCGEF)release require jamillixconds,GTPhydrolysis & GDPsetjaa-ifilRyaninoacyl ERNA placedinAsite is incorrect this milliGTPexchangefactor (GEF)seconds provide time for theEPAproper reaction.EFTS in the GE ofEFTUEFTSPeptide bond formationEFTOEFGIDP@teminalGTFreetaa,terminalCarboxyl group of I aa &PeptiEPAamino group of II aabotPrite tRNAAsite tRNA.rotateAccomadation700for bond(ARJO)formation