简介:U7smallnuclearRNA(snRNA)sequenceshavebeendescribedonlyforahandfulofanimalspeciesinthepast.Herewedescribeacomputationalsearchforfunc-tionalU7snRNAgenesthroughoutvertebratesincludingtheupstreamsequenceelementscharacteristicforsnRNAstranscribedbypolymeraseⅡ.Basedontheresultsofthissearch,wediscussthehighvariabilityofU7snRNAsinbothse-quenceandstructure,andreportonanattempttofindU7snRNAsequencesinbasaldeuterostomesandnon-drosophilidsinsectgenomesbasedonacombinationofsequence,structure,andpromoterfeatures.Duetotheextremelyshortse-quenceandthehighvariabilityinbothsequenceandstructure,nounambiguouscandidateswerefound.TheseresultscastdoubtonputativeU7homologsinevenmoredistantorganismsthatarereportedinthemostrecentreleaseoftheRfamdatabase.
简介:TheE(envelope)proteinisthesmalleststructuralproteininallcoronavirusesandistheonlyviralstructuralproteininwhichnovariationhasbeendetected.WeconductedgenomesequencingandphylogeneticanalysesofSARS-CoV.Basedongenomesequencing,wepredictedtheEproteinisatransmembrane(TM)pro-teincharacterizedbyaTMregionwithstronghydrophobicityandα-helixcon-formation.Weidentifiedasegment(NH2-_L-Cys-A-Y-Cys-Cys-N_-COOH)inthecarboxyl-terminalregionoftheEproteinthatappearstoformthreedisulfidebondswithanothersegmentofcorrespondingcysteinesinthecarboxyl-terminusoftheS(spike)protein.ThesebondspointtoapossiblestructuralassociationbetweentheEandSproteins.OurphylogeneticanalysesoftheEproteinsequencesinallpub-lishedcoronavirusesplaceSARS-CoVinanindependentgroupinCoronaviridaeandsuggestanon-humananimalorigin.