资源描述：
《冠状病毒Coronavirusl论文-2004 The Severe Acute Respiratory Syndrome Coronavirus Nsp15 Protein Is an Endoribonuclease That Prefers Manganese as a.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、JOURNALOFVIROLOGY,Nov.2004,p.1221812224Vol.78,No.220022-538X/04/$08.000DOI:10.1128/JVI.78.22.1221812224.2004Copyright©2004,AmericanSocietyforMicrobiology.AllRightsReserved.TheSevereAcuteRespiratorySyndromeCoronavirusNsp15ProteinIsanEndoribonucleaseThatPrefersManganeseasaCofactorKanchanBhard
2、waj,LindaGuarino,andC.ChengKao*DepartmentofBiochemistryandBiophysics,TexasA&MUniversity,CollegeStation,TexasReceived23April2004/Accepted9July2004Nonstructuralprotein15(Nsp15)ofthesevereacuterespiratorysyndromecoronavirus(SARS-CoV)pro-ducedinEscherichiacolihasendoribonucleaseactivitythatprefe
3、rentiallycleaved5ofuridylatesofRNAs.Blockingeitherthe5or3terminusdidnotaffectcleavage.Double-andsingle-strandedRNAswereboth2substratesforNsp15butwithdifferentkineticsforcleavage.Mnat2to10mMwasneededforoptimal2endoribonucleaseactivity,butMgandseveralotherdivalentmetalswerecapableofsuppor
4、tingonlyalow2levelofactivity.ConcentrationsofMnneededforendoribonucleaseactivityinducedsignificantconforma-tionchange(s)intheprotein,asmeasuredbychangesintryptophanfluorescence.Asimilarendoribonucleo-lyticactivitywasdetectedfortheorthologousproteinfromanothercoronavirus,demonstratingthattheen
5、doribonucleaseactivityofNsp15maybecommontocoronaviruses.Thisworkpresentsaninitialbiochemicalcharacterizationofanovelcoronavirusendoribonuclease.Thesevereacuterespiratorysyndrome(SARS)epidemicofNsp13isahelicasewiththeabilitytounwindbothDNAand2002to2003eventuallyspreadfromChinato30countries,RN
6、Aduplexes.Nsp13isalsoreportedtohavedNTPaseandwithmorethan8,000confirmedcasesandanoverallmortalityRNA5-triphosphataseactivities(6).rateofabout10%(31).Duetothelackofmorespecifican-Ingeneral,thebiochemicalcharacterizationsofthecoro-tiviralagents,onetreatmentregimenusedconsistedofcorti-navirusrep
7、lication-associatedproteinsareatanearlystage.coidsteroidsandribavirin(15,16).Thisregimenwasofun-SnijderandcolleagueshaveproposedthatNsp15hassimilar-2knownefficacyandhadseveresideeffects.Thus,thereisaitiestotheendoribonucleaseXendoU(25),aMn-depen-ne
