| IED ID | IndEnz0002007299 |
| Enzyme Type ID | protease007299 |
| Protein Name |
Frameshifted structural polyprotein p130 Cleaved into: Capsid protein EC 3.4.21.90 Coat protein C ; p62 E3/E2 ; Protein E3 Spike glycoprotein E3 ; Envelope glycoprotein E2 Spike glycoprotein E2 ; Protein TF |
| Gene Name | |
| Organism | Semliki forest virus (SFV) |
| Taxonomic Lineage | Viruses Riboviria Orthornavirae Kitrinoviricota Alsuviricetes Martellivirales Togaviridae Alphavirus (arboviruses group A) Semliki forest virus (SFV) |
| Enzyme Sequence | MNYIPTQTFYGRRWRPRPAARPWPLQATPVAPVVPDFQAQQMQQLISAVNALTMRQNAIAPARPPKPKKKKTTKPKPKTQPKKINGKTQQQKKKDKQADKKKKKPGKRERMCMKIENDCIFEVKHEGKVTGYACLVGDKVMKPAHVKGVIDNADLAKLAFKKSSKYDLECAQIPVHMRSDASKYTHEKPEGHYNWHHGAVQYSGGRFTIPTGAGKPGDSGRPIFDNKGRVVAIVLGGANEGSRTALSVVTWNKDMVTRVTPEGSEEWSAPLITAMCVLANATFPCFQPPCVPCCYENNAEATLRMLEDNVDRPGYYDLLQAALTCRNGTRHRRSVSQHFNVYKATRPYIAYCADCGAGHSCHSPVAIEAVRSEATDGMLKIQFSAQIGIDKSDNHDYTKIRYADGHAIENAVRSSLKVATSGDCFVHGTMGHFILAKCPPGEFLQVSIQDTRNAVRACRIQYHHDPQPVGREKFTIRPHYGKEIPCTTYQQTTAETVEEIDMHMPPDTPDRTLLSQQSGNVKITVGGKKVKYNCTCGTGNVGTTNSDMTINTCLIEQCHVSVTDHKKWQFNSPFVPRADEPARKGKVHIPFPLDNITCRVPMAREPTVIHGKREVTLHLHPDHPTLFSYRTLGEDPQYHEEWVTAAVERTIPVPVDGMEYHWGNNDPVRLWSQLTTEGKPHGWPHQIVQYYYGLYPAATVSAVVGMSLLALISIFASCYMLVAARSKCLTPYALTPGAAVPWTLGILCCAPRAHAASVAETMAYLWDQNQALFWLEFAAPVACILIITYCLRNVLCCCKSLSFLSATEPRGHRQSLRTFDSNAERGGVPV |
| Enzyme Length | 830 |
| Uniprot Accession Number | P0DJZ6 |
| Absorption | |
| Active Site | ACT_SITE 145; /note=Charge relay system; /evidence=ECO:0000255|PROSITE-ProRule:PRU01027; ACT_SITE 167; /note=Charge relay system; /evidence=ECO:0000250|UniProtKB:P0DOK0; ACT_SITE 219; /note=Charge relay system; /evidence=ECO:0000255|PROSITE-ProRule:PRU01027 |
| Activity Regulation | |
| Binding Site | |
| Calcium Binding | |
| catalytic Activity | CATALYTIC ACTIVITY: Reaction=Autocatalytic release of the core protein from the N-terminus of the togavirus structural polyprotein by hydrolysis of a -Trp-|-Ser- bond.; EC=3.4.21.90; Evidence={ECO:0000250|UniProtKB:P03315}; |
| DNA Binding | |
| EC Number | 3.4.21.90 |
| Enzyme Function | FUNCTION: [Capsid protein]: Forms an icosahedral capsid with a T=4 symmetry composed of 240 copies of the capsid protein surrounded by a lipid membrane through which penetrate 80 spikes composed of trimers of E1-E2 heterodimers (By similarity). The capsid protein binds to the viral RNA genome at a site adjacent to a ribosome binding site for viral genome translation following genome release (By similarity). Possesses a protease activity that results in its autocatalytic cleavage from the nascent structural protein (By similarity). 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 (By similarity). 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 (By similarity). In case of infection, new virions attach to target cells and after clathrin-mediated endocytosis their membrane fuses with the host endosomal membrane (By similarity). This leads to the release of the nucleocapsid into the cytoplasm, followed by an uncoating event necessary for the genomic RNA to become accessible (By similarity). The uncoating might be triggered by the interaction of capsid proteins with ribosomes (By similarity). Binding of ribosomes would release the genomic RNA since the same region is genomic RNA-binding and ribosome-binding (By similarity). Specifically inhibits interleukin-1 receptor-associated kinase 1/IRAK1-dependent signaling during viral entry, representing a means by which the alphaviruses may evade innate immune detection and activation prior to viral gene expression (By similarity). {ECO:0000250|UniProtKB:P03315, ECO:0000250|UniProtKB:P03316, ECO:0000250|UniProtKB:P27284}.; FUNCTION: [Protein E3]: Provides the signal sequence for p62 (E3/E2) translocation to the host endoplasmic reticulum. Mediates pH protection of E1 during secretory pathway trans- port. {ECO:0000269|PubMed:23864626}.; FUNCTION: [Envelope 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. {ECO:0000269|PubMed:1714373}.; FUNCTION: [Protein TF]: Virion component that may play a role during viral assembly. {ECO:0000269|PubMed:18822126}. |
| Temperature Dependency | |
| PH Dependency | |
| Pathway | |
| nucleotide Binding | |
| Features | Active site (3); Chain (5); Compositional bias (1); Disulfide bond (1); Domain (1); Glycosylation (4); Lipidation (4); Mutagenesis (3); Region (3); Site (3); Transmembrane (3) |
| Keywords | Autocatalytic cleavage;Capsid protein;Clathrin-mediated endocytosis of virus by host;Cleavage on pair of basic residues;Disulfide bond;Fusion of virus membrane with host endosomal membrane;Fusion of virus membrane with host membrane;Glycoprotein;Host cell membrane;Host cytoplasm;Host membrane;Host nucleus;Host-virus interaction;Hydrolase;Lipoprotein;Membrane;Palmitate;Protease;Ribosomal frameshifting;Serine protease;T=4 icosahedral capsid protein;Transmembrane;Transmembrane helix;Viral attachment to host cell;Viral envelope protein;Viral penetration into host cytoplasm;Virion;Virus endocytosis by host;Virus entry into host cell |
| Interact With | |
| Induction | |
| Subcellular Location | SUBCELLULAR LOCATION: [Capsid protein]: Virion {ECO:0000250|UniProtKB:P03316}. Host cytoplasm {ECO:0000250|UniProtKB:Q8JUX5}. Host cell membrane {ECO:0000250|UniProtKB:P03316}. Host nucleus {ECO:0000250|UniProtKB:Q8JUX5}. Note=Shuttles between the cytoplasm and the nucleus. {ECO:0000250|UniProtKB:Q8JUX5}.; SUBCELLULAR LOCATION: [p62]: Virion membrane {ECO:0000250}; Single-pass type I membrane protein {ECO:0000250}. Host cell membrane {ECO:0000250}; Single-pass type I membrane protein {ECO:0000250}.; SUBCELLULAR LOCATION: [Envelope glycoprotein E2]: Virion membrane {ECO:0000250}; Single-pass type I membrane protein {ECO:0000250}. Host cell membrane {ECO:0000250}; Single-pass type I membrane protein {ECO:0000250}.; SUBCELLULAR LOCATION: [Protein TF]: Virion {ECO:0000269|PubMed:18822126}. |
| Modified Residue | |
| Post Translational Modification | PTM: [Isoform Frameshifted 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 (By similarity). The remaining polyprotein is then targeted to the host endoplasmic reticulum, where host signal peptidase cleaves it into pE2 and TF. pE2 is further processed to mature E3 and E2 by host furin in trans-Golgi vesicle (By similarity). {ECO:0000250|UniProtKB:P03315}. |
| Signal Peptide | |
| Structure 3D | |
| Cross Reference PDB | - |
| Mapped Pubmed ID | - |
| Motif | |
| Gene Encoded By | |
| Mass | 92,349 |
| Kinetics | |
| Metal Binding | |
| Rhea ID | |
| Cross Reference Brenda |