冠状病毒Coronavirusl论文-2012 [Advances in Experimental Medicine and Biology] The Effects of Noise on Aquatic Life Volume 730 __ A New Model for.pdf

《冠状病毒Coronavirusl论文-2012 [Advances in Experimental Medicine and Biology] The Effects of Noise on Aquatic Life Volume 730 __ A New Model for.pdf》由会员上传分享，免费在线阅读，更多相关内容在学术论文-天天文库。

1、26ANEWMODELFORCORONAVIRUSTRANSCRIPTIONS.G.SawickiandD.L.SawickiDepartmentofMicrobiologyandImmunologyMedicalCollegeofOhioTole!io,Ohio43699I.ABSTRACTCoronavirusescontainanunusuallylong(27-32,000ribonucleotide)positivesenseRNAgenomethatispolyadenylatedatthe3'endandcappedatthe5'e

2、nd.Inadditiontothegenome,infectedcellscontainsubgenomicmRNAsthatforma3'co-terminalnestedsetwiththegenome.Inadditiontotheircommon3'ends,thegenomeandthesubgenomicmRNAscontainanidentical5'leadersequence.Thetranscriptionmechanismthatcoro•navirusesusetoproducesubgenomicmRNAisnotkn

3、ownandhasbeenthesubjectofspeculationsincesequencingofthesubgenomicmRNAsshowedtheymustarisebydis•continuoustranscription.Thecurrentmodelcalledleader-primedtranscriptionhassub•genomicmRNAstranscribeddirectlyfromgenome-lengthnegativestrands.Itwasbasedonthefailuretofindincoronavi

4、rusinfectedcellssubgenome-Iengthnegativestrandsorreplicationintermediatescontainingsubgenome-lengthnegativestrands.Clearly,thesestructuresexistininfectedcellsandaretranscriptionallyactive.Weproposedanewmodelforcoronavirustranscriptionwhichwecalled3'discontinuousextensionofneg

5、ativestrands.Thismodelpredictsthatsubgenome-lengthnegativestrandswouldbederiveddi•rectlybytranscriptionusingthegenomeRNAasatemplate.Thesubgenome-lengthtem•plateswouldcontainthecommon5'leadersequenceandserveastemplatesfortheproductionofsubgenomicmRNAs.Ourfindingsincludeshowing

6、that:I.Replicationin•termediates(RIs)containingsubgenome-lengthRNAexistininfectedcellsandaresepa•rablefromRIswithgenome-lengthtemplates.TheRFswithsubgenome-lengthtemplatesarenotderivedbyRNasetreatmentofRIswithgenome-lengthtemplates.2.Thesub•genome-lengthnegativestrandsareform

7、edearlyininfectionwhenRIsareaccumulatingandtherateofviralRNAsynthesisisincreasingexponentially.3.Subgenome-Iengthnegativestrandscontainattheir3'endsacomplementarycopyofthe72nucleotideleaderRNAthatisfoundinthegenomeonlyattheir5'end.4.RIswithsubgenomictemplatesCoronavirusesandA

8、rteriviruses,editedbyEnjuanesetaf.PlenumPress,NewYork,1998215216S.G.