ID POLS_SAGV Reviewed; 1253 AA. AC Q9JGK8; Q80S33; DT 30-MAY-2006, integrated into UniProtKB/Swiss-Prot. DT 01-OCT-2000, sequence version 1. DT 22-NOV-2017, entry version 91. DE RecName: Full=Structural polyprotein; DE AltName: Full=p130; DE Contains: DE RecName: Full=Capsid protein; DE EC=3.4.21.90; DE AltName: Full=Coat protein; DE Short=C; DE Contains: DE RecName: Full=p62; DE AltName: Full=E3/E2; DE Contains: DE RecName: Full=E3 protein; DE AltName: Full=Spike glycoprotein E3; DE Contains: DE RecName: Full=E2 envelope glycoprotein; DE AltName: Full=Spike glycoprotein E2; DE Contains: DE RecName: Full=6K protein; DE Contains: DE RecName: Full=E1 envelope glycoprotein; DE AltName: Full=Spike glycoprotein E1; OS Sagiyama virus (SAGV). OC Viruses; ssRNA viruses; ssRNA positive-strand viruses, no DNA stage; OC Togaviridae; Alphavirus; SFV complex. OX NCBI_TaxID=59303; OH NCBI_TaxID=7158; Aedes. OH NCBI_TaxID=7178; Culex tritaeniorhynchus (Mosquito). OH NCBI_TaxID=9796; Equus caballus (Horse). OH NCBI_TaxID=9606; Homo sapiens (Human). OH NCBI_TaxID=9823; Sus scrofa (Pig). RN [1] RP NUCLEOTIDE SEQUENCE [GENOMIC RNA]. RX PubMed=10769079; RA Shirako Y., Yamaguchi Y.; RT "Genome structure of Sagiyama virus and its relatedness to other RT alphaviruses."; RL J. Gen. Virol. 81:1353-1360(2000). RN [2] RP NUCLEOTIDE SEQUENCE [GENOMIC RNA]. RA Kinney R.M., Pfeffer M.; RT "Nucleotide sequence analyses of the 26S mRNAs of viruses of the genus RT Alphavirus."; RL Submitted (JAN-2001) to the EMBL/GenBank/DDBJ databases. CC -!- FUNCTION: Capsid protein possesses a protease activity that CC results in its autocatalytic cleavage from the nascent structural CC protein. Following its self-cleavage, the capsid protein CC transiently associates with ribosomes, binds to viral RNA and CC rapidly assembles into icosahedric core particles. The resulting CC nucleocapsid eventually associates with the cytoplasmic domain of CC E2 at the cell membrane, leading to budding and formation of CC mature virions. New virions attach to target cells, and after CC endocytosis their membrane fuses with the target cell membrane. CC This leads to the release of the nucleocapsid into the cytoplasm, CC followed by an uncoating event necessary for the genomic RNA to CC become accessible. The uncoating might be triggered by the CC interaction of capsid proteins with ribosomes. Binding of CC ribosomes would release the genomic RNA since the same region is CC genomic RNA-binding and ribosome-binding (By similarity). CC {ECO:0000250}. CC -!- FUNCTION: E3 protein's function is unknown. {ECO:0000250}. CC -!- FUNCTION: E2 is responsible for viral attachment to target host CC cell, by binding to the cell receptor. Synthesized as a p62 CC precursor which is processed by furin at the cell membrane just CC before virion budding, giving rise to E2-E1 heterodimer. The p62- CC E1 heterodimer is stable, whereas E2-E1 is unstable and dissociate CC at low pH. p62 is processed at the last step, presumably to avoid CC E1 fusion activation before its final export to cell surface. E2 CC C-terminus contains a transitory transmembrane that would be CC disrupted by palmitoylation, resulting in reorientation of the C- CC terminal tail from lumenal to cytoplasmic side. This step is CC critical since E2 C-terminus is involved in budding by interacting CC with capsid proteins. This release of E2 C-terminus in cytoplasm CC occurs lately in protein export, and precludes premature assembly CC of particles at the endoplasmic reticulum membrane (By CC similarity). {ECO:0000250}. CC -!- FUNCTION: 6K is a constitutive membrane protein involved in virus CC glycoprotein processing, cell permeabilization, and the budding of CC viral particles. Disrupts the calcium homeostasis of the cell, CC probably at the endoplasmic reticulum level. This leads to CC cytoplasmic calcium elevation. Because of its lipophilic CC properties, the 6K protein is postulated to influence the CC selection of lipids that interact with the transmembrane domains CC of the glycoproteins, which, in turn, affects the deformability of CC the bilayer required for the extreme curvature that occurs as CC budding proceeds. Present in low amount in virions, about 3% CC compared to viral glycoproteins (By similarity). {ECO:0000250}. CC -!- FUNCTION: E1 is a class II viral fusion protein. Fusion activity CC is inactive as long as E1 is bound to E2 in mature virion. After CC virus attachment to target cell and endocytosis, acidification of CC the endosome would induce dissociation of E1/E2 heterodimer and CC concomitant trimerization of the E1 subunits. This E1 trimer is CC fusion active, and promotes release of viral nucleocapsid in CC cytoplasm after endosome and viral membrane fusion. Efficient CC fusion requires the presence of cholesterol and sphingolipid in CC the target membrane (By similarity). {ECO:0000250}. CC -!- CATALYTIC ACTIVITY: Autocatalytic release of the core protein from CC the N-terminus of the togavirus structural polyprotein by CC hydrolysis of a -Trp-|-Ser- bond. CC -!- SUBUNIT: p62 and E1 form a heterodimer shortly after synthesis. CC Processing of p62 into E2 and E3 results in a heterodimer of E2 CC and E1. Spike at virion surface are constituted of three E2-E1 CC heterodimers. After target cell attachment and endocytosis, E1 CC change conformation to form homotrimers (By similarity). CC {ECO:0000250}. CC -!- SUBCELLULAR LOCATION: Capsid protein: Virion {ECO:0000250}. Host CC cytoplasm {ECO:0000250}. CC -!- SUBCELLULAR LOCATION: p62: Virion membrane {ECO:0000250}; Single- CC pass type I membrane protein {ECO:0000250}. Host cell membrane CC {ECO:0000250}; Single-pass type I membrane protein {ECO:0000250}. CC -!- SUBCELLULAR LOCATION: E2 envelope glycoprotein: Virion membrane CC {ECO:0000250}; Single-pass type I membrane protein {ECO:0000250}. CC Host cell membrane {ECO:0000250}; Single-pass type I membrane CC protein {ECO:0000250}. CC -!- SUBCELLULAR LOCATION: E1 envelope glycoprotein: Virion membrane CC {ECO:0000250}; Single-pass type I membrane protein {ECO:0000250}. CC Host cell membrane {ECO:0000250}; Single-pass type I membrane CC protein {ECO:0000250}. CC -!- SUBCELLULAR LOCATION: 6K protein: Host cell membrane CC {ECO:0000250}; Multi-pass membrane protein {ECO:0000250}. Virion CC membrane {ECO:0000250}; Multi-pass membrane protein {ECO:0000250}. CC -!- PTM: Specific enzymatic cleavages in vivo yield mature proteins. CC Capsid protein is auto-cleaved during polyprotein translation, CC unmasking p62 signal peptide. The remaining polyprotein is then CC targeted to the endoplasmic reticulum, where host signal peptidase CC cleaves it into p62, 6K and E1 proteins. p62 is further processed CC to mature E3 and E2 by host furin in trans-Golgi vesicle (By CC similarity). {ECO:0000250}. CC -!- PTM: E2 and 6K are palmitoylated via thioester bonds. CC {ECO:0000250}. CC -!- MISCELLANEOUS: Structural polyprotein is translated from a CC subgenomic RNA synthesized during togavirus replication. CC --------------------------------------------------------------------------- CC Copyrighted by the UniProt Consortium, see https://www.uniprot.org/terms CC Distributed under the Creative Commons Attribution (CC BY 4.0) License CC --------------------------------------------------------------------------- DR EMBL; AB032553; BAA92847.1; -; Genomic_RNA. DR EMBL; AF339483; AAO33337.1; -; Genomic_RNA. DR ProteinModelPortal; Q9JGK8; -. DR SMR; Q9JGK8; -. DR MEROPS; S03.001; -. DR OrthoDB; VOG0900008L; -. DR Proteomes; UP000007138; Genome. DR GO; GO:0030430; C:host cell cytoplasm; IEA:UniProtKB-SubCell. DR GO; GO:0020002; C:host cell plasma membrane; IEA:UniProtKB-SubCell. DR GO; GO:0016021; C:integral component of membrane; IEA:UniProtKB-KW. DR GO; GO:0039619; C:T=4 icosahedral viral capsid; IEA:UniProtKB-KW. DR GO; GO:0055036; C:virion membrane; IEA:UniProtKB-SubCell. DR GO; GO:0004252; F:serine-type endopeptidase activity; IEA:InterPro. DR GO; GO:0005198; F:structural molecule activity; IEA:InterPro. DR GO; GO:0039654; P:fusion of virus membrane with host endosome membrane; IEA:UniProtKB-KW. DR GO; GO:0019062; P:virion attachment to host cell; IEA:UniProtKB-KW. DR Gene3D; 2.60.40.350; -; 1. DR InterPro; IPR002548; Alpha_E1_glycop. DR InterPro; IPR000936; Alpha_E2_glycop. DR InterPro; IPR002533; Alpha_E3_glycop. DR InterPro; IPR000336; Flavivir/Alphavir_Ig-like_sf. DR InterPro; IPR036253; Glycoprot_cen/dimer_sf. DR InterPro; IPR014756; Ig_E-set. DR InterPro; IPR009003; Peptidase_S1_PA. DR InterPro; IPR000930; Peptidase_S3. DR Pfam; PF01589; Alpha_E1_glycop; 1. DR Pfam; PF00943; Alpha_E2_glycop; 1. DR Pfam; PF01563; Alpha_E3_glycop; 1. DR Pfam; PF00944; Peptidase_S3; 1. DR PRINTS; PR00798; TOGAVIRIN. DR SUPFAM; SSF50494; SSF50494; 1. DR SUPFAM; SSF56983; SSF56983; 1. DR SUPFAM; SSF81296; SSF81296; 1. DR PROSITE; PS51690; ALPHAVIRUS_CP; 1. PE 3: Inferred from homology; KW Capsid protein; Cleavage on pair of basic residues; Complete proteome; KW Disulfide bond; Fusion of virus membrane with host endosomal membrane; KW Fusion of virus membrane with host membrane; Glycoprotein; KW Host cell membrane; Host cytoplasm; Host membrane; KW Host-virus interaction; Hydrolase; Lipoprotein; Membrane; Palmitate; KW Protease; Serine protease; Signal; T=4 icosahedral capsid protein; KW Transmembrane; Transmembrane helix; Viral attachment to host cell; KW Viral penetration into host cytoplasm; Virion; KW Virus entry into host cell. FT CHAIN 1 268 Capsid protein. {ECO:0000250}. FT /FTId=PRO_0000238766. FT CHAIN 269 754 p62. {ECO:0000250}. FT /FTId=PRO_0000238767. FT CHAIN 269 332 E3 protein. {ECO:0000250}. FT /FTId=PRO_0000238768. FT SIGNAL 269 284 Not cleaved. {ECO:0000255}. FT CHAIN 333 754 E2 envelope glycoprotein. {ECO:0000250}. FT /FTId=PRO_0000238769. FT CHAIN 755 815 6K protein. {ECO:0000250}. FT /FTId=PRO_0000238770. FT CHAIN 816 1253 E1 envelope glycoprotein. {ECO:0000250}. FT /FTId=PRO_0000238771. FT TOPO_DOM 333 694 Extracellular. {ECO:0000255}. FT TRANSMEM 695 715 Helical. {ECO:0000255}. FT TOPO_DOM 716 754 Cytoplasmic. {ECO:0000255}. FT TOPO_DOM 755 769 Extracellular. {ECO:0000255}. FT TRANSMEM 770 790 Helical. {ECO:0000255}. FT TOPO_DOM 791 792 Cytoplasmic. {ECO:0000255}. FT TRANSMEM 793 813 Helical. {ECO:0000255}. FT TOPO_DOM 814 815 Extracellular. {ECO:0000255}. FT TOPO_DOM 816 1227 Extracellular. {ECO:0000255}. FT TRANSMEM 1228 1248 Helical. {ECO:0000255}. FT TOPO_DOM 1249 1253 Cytoplasmic. {ECO:0000255}. FT DOMAIN 120 268 Peptidase S3. {ECO:0000255|PROSITE- FT ProRule:PRU01027}. FT REGION 1 114 Intrinsically disordered, in contact with FT genomic RNA in nucleocapsid. FT {ECO:0000255}. FT REGION 94 107 Ribosome-binding. {ECO:0000250}. FT REGION 727 747 Transient transmembrane before p62-6K FT protein processing. {ECO:0000255}. FT REGION 899 916 E1 fusion peptide loop. {ECO:0000250}. FT ACT_SITE 146 146 Charge relay system. FT {ECO:0000255|PROSITE-ProRule:PRU01027}. FT ACT_SITE 152 152 Charge relay system. FT {ECO:0000255|PROSITE-ProRule:PRU01027}. FT ACT_SITE 220 220 Charge relay system. FT {ECO:0000255|PROSITE-ProRule:PRU01027}. FT SITE 268 269 Cleavage; by capsid protein. FT {ECO:0000250}. FT SITE 332 333 Cleavage; by host furin. {ECO:0000250}. FT SITE 754 755 Cleavage; by host signal peptidase. FT {ECO:0000250}. FT SITE 815 816 Cleavage; by host signal peptidase. FT {ECO:0000250}. FT LIPID 727 727 S-palmitoyl cysteine; by host. FT {ECO:0000250}. FT LIPID 747 747 S-palmitoyl cysteine; by host. FT {ECO:0000250}. FT LIPID 748 748 S-palmitoyl cysteine; by host. FT {ECO:0000250}. FT CARBOHYD 279 279 N-linked (GlcNAc...) asparagine; by host. FT {ECO:0000255}. FT CARBOHYD 594 594 N-linked (GlcNAc...) asparagine; by host. FT {ECO:0000255}. FT CARBOHYD 956 956 N-linked (GlcNAc...) asparagine; by host. FT {ECO:0000255}. FT DISULFID 864 929 {ECO:0000250}. FT DISULFID 877 909 {ECO:0000250}. FT DISULFID 878 911 {ECO:0000250}. FT DISULFID 883 893 {ECO:0000250}. FT DISULFID 1074 1086 {ECO:0000250}. FT DISULFID 1116 1191 {ECO:0000250}. FT DISULFID 1121 1195 {ECO:0000250}. FT DISULFID 1143 1185 {ECO:0000250}. FT VARIANT 403 403 V -> A. FT VARIANT 519 519 D -> N. FT VARIANT 872 872 P -> S. FT VARIANT 1242 1242 A -> V. SQ SEQUENCE 1253 AA; 138060 MW; D8F11776CF2152F2 CRC64; MNYIPTQTFY GRRWRPRPAF RPWRVPMQPA PPMVIPELQT PIVQAQQMQQ LISAVSALTT KQNGKAPKKP KKKPQKAKAK KNEQQKKNEN KKPPPKQKNL AKKKKPGKRE RMCMKIENDC IFEVKLDGKV TGYACLVGDK VMKPAHVKGV IDNPDLAKLT YKKSSKYDLE CAQIPVHMKS DASKYTHEKP EGHYNWHHGA VQYSGGRFTI PTGAGKPGDS GRPIFDNKGR VVAIVLGGAN EGARTALSVV TWTKDMVTRY TPEGTEEWSA ALMMCVLANV TFPCSEPACA PCCYEKQPEQ TLRMLEDNVD RPGYYDLLEA TMTCNNSARH RRSVTEHFNV YKATKPYLAY CADCGDGQFC YSPVAIEKIR DEASDGMIKI QVAAQIGINK RGTHEHNKIR YIVGHYMKEA NRDSLQVHTS GVCAIRGTMG HFIVAYCPPG DELKVQFQDA ESHTQACKVQ YKHDPAPVGR EKFTVRPHFG IEVPCTTYQL TTAPTEEEID MHTPPDIPDI TLLSQQSGDV KITAGGKTIR YNCTCGSGNV GTTSSDKTIN SCKIAQCHAA VTNHDKWQYT SSFVPRADQL PRKGKVHVPF PLTNSTCRVP LARAPGVTYG KRELTVKLHP DHPTLLTYRS LGADPRPYEE WIDRYVERTI PVTEDGIEYR WGNNPPVRLW AQLTTEGKPH GWPHEIILYY YGLYPAATIA AVSAAGLAVV LSLLASCYMF ATARRKCLTP YALTPGAVVP VTLGVLCCAP RAHAASFAES MAYLWDENQT LFWLELATPL AAIIILVCCL KNLLCCCQPL SFLVLVSLGT PVVKSYEHTA TIPNVVGFPY KAHIERNGFS PMTLQLEVLG TSLEPTLNLE YITCEYKTVV PPPYIKCCGA SECRSMERPD YQCQVYTGVY PFMWGGAYCF CDTENTQLSE AYVDRSDVCK HDHAAAYKAH TAAMKATIRI SYGNLNQTTT AFVNGEHTVT VGGSRFTFGP ISTAWTPFDN KIVVYKNDVY NQDFPPYGSG QPGRFGDVQS RTVESKDLYA NTALKLSRPS SGTVHVPYTQ TPSGFKYWIK ERGTSLNDKA PFGCVIKTNP VRAENCAVGN IPVSMDIPDS AFTRVIDAPA VTNLECQVAV CTHSSDFGGI ATLTFKTDKP GKCAVHSHSN VATIQEAAVD IKTDGKITLH FSTASASPAF MVSVCSAKTT CMAACEPPKD HIVPYGASHN NQVFPDMSGT AMTWVQRVAG GLGGLTLAAV AALILVTCVT MRR //