简介：Eachsecretion(Sec)machineryminimallyconsistsofthreeintegralinnermembranepro-teinsSecYEG.InordertoknowthedistributionpatternoftheSeccomplexinStreptococcusmutans,weexploredthesubcellularlocalizationofSecY.Theanti-secYantibodywasexaminedonWesternblotstoevaluatespecificity.Anindirectpost-embeddingimmunogoldmethodwasusedtodeterminethesubcel-lularlocalizationoftheSecYinthecytoplasmicmembraneoftheStreptococcusmutansGS-5.Immuno-blottingexperimentsshowedthattheanti-secYantibodyspecificallyrecognizedasinglebandofabout47.8kDa.Immunogoldelectronmicroscopyimageofsectionwithanti-secYantibodyrevealedasingleintensefocusofgoldparticlesatadiscretelocationonthecytoplasmicmembraneoftheStreptococcusmutansGS-5.SecYclusteredtoanasyrmnetricmicrodomain,whichindicatedforthefirsttimethatSeccomplexpresentedauni-siteonthecytoplasmicmembraneofStreptococcusmutans.