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Protein

Structural polyprotein

Gene
N/A
Organism
O'nyong-nyong virus (strain Igbo Ora) (ONNV) (Igbo Ora virus)
Status
Reviewed-Annotation score: -Protein inferred from homologyi

Functioni

Capsid protein: Possesses a protease activity that results in its autocatalytic cleavage from the nascent structural protein. Following its self-cleavage, the capsid protein transiently associates with ribosomes, and within several minutes the protein binds to viral RNA and rapidly assembles into icosahedric core particles. The resulting nucleocapsid eventually associates with the cytoplasmic domain of the spike glycoprotein E2 at the cell membrane, leading to budding and formation of mature virions. In case of infection, new virions attach to target cells and after clathrin-mediated endocytosis their membrane fuses with the host endosomal membrane. This leads to the release of the nucleocapsid into the cytoplasm, followed by an uncoating event necessary for the genomic RNA to become accessible. The uncoating might be triggered by the interaction of capsid proteins with ribosomes. Binding of ribosomes would release the genomic RNA since the same region is genomic RNA-binding and ribosome-binding.By similarity
Assembly protein E3: Provides the signal sequence for the translocation of the precursor of protein E3/E2 to the host endoplasmic reticulum. Mediates pH protection of spike glycoprotein E1 during the transport via the secretory pathway.By similarity
Spike glycoprotein E2: Plays a role in viral attachment to target host cell, by binding to the cell receptor. Synthesized as a p62 precursor which is processed by furin at the cell membrane just before virion budding, giving rise to E2-E1 heterodimer. The p62-E1 heterodimer is stable, whereas E2-E1 is unstable and dissociate at low pH. p62 is processed at the last step, presumably to avoid E1 fusion activation before its final export to cell surface. E2 C-terminus contains a transitory transmembrane that would be disrupted by palmitoylation, resulting in reorientation of the C-terminal tail from lumenal to cytoplasmic side. This step is critical since E2 C-terminus is involved in budding by interacting with capsid proteins. This release of E2 C-terminus in cytoplasm occurs lately in protein export, and precludes premature assembly of particles at the endoplasmic reticulum membrane.By similarity
6K protein: Constitutive membrane protein involved in virus glycoprotein processing, cell permeabilization, and the budding of viral particles. Disrupts the calcium homeostasis of the cell, probably at the endoplasmic reticulum level. This leads to cytoplasmic calcium elevation. Because of its lipophilic properties, the 6K protein is postulated to influence the selection of lipids that interact with the transmembrane domains of the glycoproteins, which, in turn, affects the deformability of the bilayer required for the extreme curvature that occurs as budding proceeds. Present in low amount in virions, about 3% compared to viral glycoproteins.By similarity
Spike glycoprotein E1: Class II viral fusion protein. Fusion activity is inactive as long as E1 is bound to E2 in mature virion. After virus attachment to target cell and endocytosis, acidification of the endosome would induce dissociation of E1/E2 heterodimer and concomitant trimerization of the E1 subunits. This E1 trimer is fusion active, and promotes release of viral nucleocapsid in cytoplasm after endosome and viral membrane fusion. Efficient fusion requires the presence of cholesterol and sphingolipid in the target membrane. Fusion is optimal at levels of about 1 molecule of cholesterol per 2 molecules of phospholipids, and is specific for sterols containing a 3-beta-hydroxyl group.By similarity

Miscellaneous

Structural polyprotein: Translated from a subgenomic RNA synthesized during togavirus replication.By similarity

Catalytic activityi

Autocatalytic release of the core protein from the N-terminus of the togavirus structural polyprotein by hydrolysis of a -Trp-|-Ser- bond.By similarity

Sites

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Active sitei138Charge relay systemPROSITE-ProRule annotation1
Active sitei160Charge relay systemPROSITE-ProRule annotation1
Active sitei212Charge relay systemPROSITE-ProRule annotation1

GO - Molecular functioni

GO - Biological processi

Keywordsi

Molecular functionHydrolase, Protease, Serine protease
Biological processFusion of virus membrane with host endosomal membrane, Fusion of virus membrane with host membrane, Host-virus interaction, Viral attachment to host cell, Viral penetration into host cytoplasm, Virus entry into host cell

Protein family/group databases

MEROPSiS03.001

Names & Taxonomyi

Protein namesi
Recommended name:
Structural polyprotein
Alternative name(s):
p130
Cleaved into the following 6 chains:
Alternative name(s):
Coat protein
Short name:
C
Alternative name(s):
p62
pE2
Alternative name(s):
E2 envelope glycoprotein
Alternative name(s):
E1 envelope glycoprotein
OrganismiO'nyong-nyong virus (strain Igbo Ora) (ONNV) (Igbo Ora virus)
Taxonomic identifieri79899 [NCBI]
Taxonomic lineageiVirusesssRNA virusesssRNA positive-strand viruses, no DNA stageTogaviridaeAlphavirus
Virus hostiAnopheles [TaxID: 44482]
Homo sapiens (Human) [TaxID: 9606]
Proteomesi
  • UP000008382 Componenti: Genome

Subcellular locationi

Capsid protein :
  • Virion By similarity
  • Host cytoplasm By similarity
  • Host cell membrane By similarity
Spike glycoprotein E2 :
6K protein :
Spike glycoprotein E1 :

Topology

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Topological domaini325 – 691ExtracellularSequence analysisAdd BLAST367
Transmembranei692 – 712HelicalSequence analysisAdd BLAST21
Topological domaini713 – 747CytoplasmicSequence analysisAdd BLAST35
Topological domaini748 – 762ExtracellularSequence analysisAdd BLAST15
Transmembranei763 – 783HelicalSequence analysisAdd BLAST21
Topological domaini784 – 787CytoplasmicSequence analysis4
Transmembranei788 – 808HelicalSequence analysisAdd BLAST21
Topological domaini809 – 1223ExtracellularSequence analysisAdd BLAST415
Transmembranei1224 – 1244HelicalSequence analysisAdd BLAST21
Topological domaini1245 – 1247CytoplasmicSequence analysis3

GO - Cellular componenti

Keywords - Cellular componenti

Capsid protein, Host cell membrane, Host cytoplasm, Host membrane, Membrane, T=4 icosahedral capsid protein, Virion

PTM / Processingi

Molecule processing

Feature keyPosition(s)DescriptionActionsGraphical viewLength
ChainiPRO_00002387601 – 260Capsid proteinBy similarityAdd BLAST260
ChainiPRO_0000238761261 – 747Precursor of protein E3/E2By similarityAdd BLAST487
ChainiPRO_0000238762261 – 324Assembly protein E3By similarityAdd BLAST64
ChainiPRO_0000238763325 – 747Spike glycoprotein E2By similarityAdd BLAST423
ChainiPRO_0000238764748 – 8086K proteinBy similarityAdd BLAST61
ChainiPRO_0000238765809 – 1247Spike glycoprotein E1By similarityAdd BLAST439

Amino acid modifications

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Glycosylationi272N-linked (GlcNAc...) asparagine; by hostSequence analysis1
Glycosylationi587N-linked (GlcNAc...) asparagine; by hostSequence analysis1
Lipidationi720S-palmitoyl cysteine; by hostBy similarity1
Lipidationi740S-palmitoyl cysteine; by hostBy similarity1
Lipidationi741S-palmitoyl cysteine; by hostBy similarity1
Disulfide bondi857 ↔ 922By similarity
Disulfide bondi870 ↔ 902By similarity
Disulfide bondi871 ↔ 904By similarity
Disulfide bondi876 ↔ 886By similarity
Glycosylationi949N-linked (GlcNAc...) asparagine; by hostSequence analysis1
Disulfide bondi1067 ↔ 1079By similarity
Disulfide bondi1109 ↔ 1184By similarity
Disulfide bondi1114 ↔ 1188By similarity
Disulfide bondi1136 ↔ 1178By similarity

Post-translational modificationi

Structural polyprotein: Specific enzymatic cleavages in vivo yield mature proteins. Capsid protein is auto-cleaved during polyprotein translation, unmasking a signal peptide at the N-terminus of the precursor of E3/E2. The remaining polyprotein is then targeted to the host endoplasmic reticulum, where host signal peptidase cleaves it into pE2, 6K and E1 proteins. pE2 is further processed to mature E3 and E2 by host furin in trans-Golgi vesicle.By similarity
Spike glycoprotein E2: Palmitoylated via thioester bonds. These palmitoylations may induce disruption of the C-terminus transmembrane. This would result in the reorientation of E2 C-terminus from lumenal to cytoplasmic side.By similarity
Spike glycoprotein E1: N-glycosylated.By similarity
Spike glycoprotein E2: N-glycosylated.By similarity
Assembly protein E3: N-glycosylated.By similarity
6K protein: Palmitoylated via thioester bonds.By similarity

Sites

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Sitei260 – 261Cleavage; by autolysisBy similarity2
Sitei324 – 325Cleavage; by host furinBy similarity2
Sitei747 – 748Cleavage; by host signal peptidaseBy similarity2
Sitei808 – 809Cleavage; by host signal peptidaseBy similarity2

Keywords - PTMi

Cleavage on pair of basic residues, Disulfide bond, Glycoprotein, Lipoprotein, Palmitate

Proteomic databases

PRIDEiO90371

Interactioni

Subunit structurei

Precursor of protein E3/E2: The precursor of protein E3/E2 and E1 form a heterodimer shortly after synthesis. Spike glycoprotein E1: The precursor of protein E3/E2 and E1 form a heterodimer shortly after synthesis. Spike glycoprotein E1: Processing of the precursor of protein E3/E2 into E2 and E3 results in a heterodimer of the spike glycoproteins E2 and E1. Spike glycoprotein E2: Processing of the precursor of protein E3/E2 into E2 and E3 results in a heterodimer of the spike glycoproteins E2 and E1. Spike glycoprotein E1: Spike at virion surface are constituted of three E2-E1 heterodimers. Spike glycoprotein E2: Spike at virion surface are constituted of three E2-E1 heterodimers. Spike glycoprotein E1: After target cell attachment and endocytosis, E1 change conformation to form homotrimers. 6K protein: Interacts with spike glycoprotein E1. 6K protein: Interacts with spike glycoprotein E2. Spike glycoprotein E1: Interacts with 6K protein. Spike glycoprotein E2: Interacts with 6K protein.By similarity

Structurei

3D structure databases

ProteinModelPortaliO90371
SMRiO90371
ModBaseiSearch...
MobiDBiSearch...

Family & Domainsi

Domains and Repeats

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Domaini112 – 260Peptidase S3PROSITE-ProRule annotationAdd BLAST149

Region

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Regioni1 – 106Intrinsically disordered, in contact with genomic RNA in nucleocapsidSequence analysisAdd BLAST106
Regioni86 – 99Ribosome-bindingBy similarityAdd BLAST14
Regioni261 – 273Functions as an uncleaved signal peptide for the precursor of protein E3/E2By similarityAdd BLAST13
Regioni720 – 740Transient transmembrane before p62-6K protein processingSequence analysisAdd BLAST21
Regioni892 – 909E1 fusion peptide loopBy similarityAdd BLAST18

Domaini

Structural polyprotein: As soon as the capsid protein has been autocleaved, an internal uncleaved signal peptide directs the remaining polyprotein to the endoplasmic reticulum.By similarity

Keywords - Domaini

Transmembrane, Transmembrane helix

Phylogenomic databases

OrthoDBiVOG09000271

Family and domain databases

Gene3Di2.60.40.350, 1 hit
2.60.98.10, 3 hits
InterProiView protein in InterPro
IPR002548 Alpha_E1_glycop
IPR000936 Alpha_E2_glycop
IPR002533 Alpha_E3_glycop
IPR000336 Flavivir/Alphavir_Ig-like_sf
IPR036253 Glycoprot_cen/dimer_sf
IPR038055 Glycoprot_E_dimer_dom
IPR014756 Ig_E-set
IPR009003 Peptidase_S1_PA
IPR000930 Peptidase_S3
PfamiView protein in Pfam
PF01589 Alpha_E1_glycop, 1 hit
PF00943 Alpha_E2_glycop, 1 hit
PF01563 Alpha_E3_glycop, 1 hit
PF00944 Peptidase_S3, 1 hit
PRINTSiPR00798 TOGAVIRIN
SUPFAMiSSF50494 SSF50494, 1 hit
SSF56983 SSF56983, 1 hit
SSF81296 SSF81296, 1 hit
PROSITEiView protein in PROSITE
PS51690 ALPHAVIRUS_CP, 1 hit

Sequencei

Sequence statusi: Complete.

Sequence processingi: The displayed sequence is further processed into a mature form.

O90371-1 [UniParc]FASTAAdd to basket

« Hide

        10         20         30         40         50
MEFIPAQTYY NRRYQPRPWT QRPTIQVIRP KPRRRRPAGQ LAQLISAVSR
60 70 80 90 100
LALRTVPQKP RRTRKIKKQK QVKQEQQSTR NQKKKAPKQK QTQKKKRPGR
110 120 130 140 150
RERMCMKIEN DCIFEVKHEG KVTGYACLVG DKVMKPAHVK GTIDNADLAK
160 170 180 190 200
LAFKRSSKYD LECAQIPVHM KSDASKFTHE KPEGYYNWHH GAVQYSGGRF
210 220 230 240 250
TIPTGAGKPG DSGRPIFDNK GRVVAIVLGG ANEGTRTALS VVTWNKDIVT
260 270 280 290 300
KITPEGSVEW SLALPVMCLL ANTTFPCSQP PCAPCCYEKK PEETLRMLED
310 320 330 340 350
NVMQPGYYQL LDSALACSQH RQRRNARENF NVYKVTRPYL AHCPDCGEGH
360 370 380 390 400
SCHSPIALER IRSEATDGTL KIQVSLQIGI KTADSHDWTK LRYMDSHTPV
410 420 430 440 450
DADRSGLFVR TSAPCTITGT MGHFILARCP KGETLTVGFV DSRRISHTCM
460 470 480 490 500
HPFHHEPPLI GREKFHSRPQ HGKELPCSTY VHTTAATTEE IEVHMPPDTP
510 520 530 540 550
DYTLMTQQAG NVKITVDGQT VRYKCKCDGS NEGLITTDKV INNCKVDQCH
560 570 580 590 600
TAVTNHKKWQ YNSPLTPRNS EQGDRKGKIH IPFPLVNTTC RVPKARNPTV
610 620 630 640 650
TYGKNRVTLL LYPDHPTLLS YRAMGRIPDY HEEWITSKKE ISITVPAEGL
660 670 680 690 700
EVTWGNNDPY KYWPQLSTNG TAHGHPHEII LYYYELYPTT TIAVLAAASI
710 720 730 740 750
VVASLVGLSL GMCICARRRC ITPYELTPGA TIPFLLGILC CVKTAKAASY
760 770 780 790 800
YEAATYLWNE QQPLFWLQLL IPLSAAIVVC NCLKLLPCCC KTLTFLAVMS
810 820 830 840 850
IGARTVSAYE HATVIPNTVG VPYKTLVSRP GYSPMVLEME LQSVTLEPTL
860 870 880 890 900
FLDYITCEYK TITPSPYVKC CGTAECKAKN LPDYNCKVFT GVYPFMWGGA
910 920 930 940 950
YCFCDAENTQ LSEAHVEKSE SCKTEFASAY RAHTASVSAK LRVFYQGNNI
960 970 980 990 1000
TVSAYANGDH AVTVKDAKFV IGPLSSAWSP FDNKIVVYKG EVYNMDYPPF
1010 1020 1030 1040 1050
GAGRPGQFGD IQSRTPDSKD VYANTQLILQ RPAAGAIHVP YSQAPSGFKY
1060 1070 1080 1090 1100
WLKEKGASLQ HTAPFGCQIA TNPVRAVNCA VGNIPVSIDI PDAAFTRVTD
1110 1120 1130 1140 1150
APSVTDMSCE VASCTHSSDF GGAAVIKYTA SKKGKCAVHS LTNAVTIREP
1160 1170 1180 1190 1200
NVDVEGTAQL QIAFSTALAS AEFKVQICST QVHCSATCHP PKDHIVNYPS
1210 1220 1230 1240
PHTTLGVQDI STTAMSWVQK ITGGVGLVVA IAALILIIVL CVSFSRH
Length:1,247
Mass (Da):138,123
Last modified:November 1, 1998 - v1
Checksum:iCD92707A7AD9B6D0
GO

Sequence databases

Select the link destinations:
EMBLi
GenBanki
DDBJi
Links Updated
AF079457 Genomic RNA Translation: AAC97207.1

Similar proteinsi

Entry informationi

Entry nameiPOLS_ONNVI
AccessioniPrimary (citable) accession number: O90371
Entry historyiIntegrated into UniProtKB/Swiss-Prot: May 30, 2006
Last sequence update: November 1, 1998
Last modified: May 23, 2018
This is version 105 of the entry and version 1 of the sequence. See complete history.
Entry statusiReviewed (UniProtKB/Swiss-Prot)
Annotation programViral Protein Annotation Program

Miscellaneousi

Keywords - Technical termi

Complete proteome

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