| IED ID | IndEnz0002010214 | 
| Enzyme Type ID | protease010214 | 
| Protein Name | Spike glycoprotein S glycoprotein E2 Peplomer protein Cleaved into: Spike protein S1; Spike protein S2; Spike protein S2' | 
| Gene Name | S 2 | 
| Organism | Avian infectious bronchitis virus (strain Beaudette) (IBV) | 
| Taxonomic Lineage | Viruses Riboviria Orthornavirae Pisuviricota Pisoniviricetes Nidovirales Cornidovirineae Coronaviridae Orthocoronavirinae Gammacoronavirus Igacovirus Avian coronavirus Infectious bronchitis virus Avian infectious bronchitis virus (strain Beaudette) (IBV) | 
| Enzyme Sequence | MLVTPLLLVTLLCALCSAVLYDSSSYVYYYQSAFRPPSGWHLQGGAYAVVNISSEFNNAGSSSGCTVGIIHGGRVVNASSIAMTAPSSGMAWSSSQFCTAHCNFSDTTVFVTHCYKHGGCPLTGMLQQNLIRVSAMKNGQLFYNLTVSVAKYPTFRSFQCVNNLTSVYLNGDLVYTSNETIDVTSAGVYFKAGGPITYKVMREVKALAYFVNGTAQDVILCDGSPRGLLACQYNTGNFSDGFYPFTNSSLVKQKFIVYRENSVNTTCTLHNFIFHNETGANPNPSGVQNIQTYQTKTAQSGYYNFNFSFLSSFVYKESNFMYGSYHPSCKFRLETINNGLWFNSLSVSIAYGPLQGGCKQSVFKGRATCCYAYSYGGPSLCKGVYSGELDHNFECGLLVYVTKSGGSRIQTATEPPVITQNNYNNITLNTCVDYNIYGRTGQGFITNVTDSAVSYNYLADAGLAILDTSGSIDIFVVQGEYGLNYYKVNPCEDVNQQFVVSGGKLVGILTSRNETGSQLLENQFYIKITNGTRRFRRSITENVANCPYVSYGKFCIKPDGSIATIVPKQLEQFVAPLFNVTENVLIPNSFNLTVTDEYIQTRMDKVQINCLQYVCGSSLDCRKLFQQYGPVCDNILSVVNSVGQKEDMELLNFYSSTKPAGFNTPVLSNVSTGEFNISLLLTNPSSRRKRSLIEDLLFTSVESVGLPTNDAYKNCTAGPLGFFKDLACAREYNGLLVLPPIITAEMQALYTSSLVASMAFGGITAAGAIPFATQLQARINHLGITQSLLLKNQEKIAASFNKAIGHMQEGFRSTSLALQQIQDVVSKQSAILTETMASLNKNFGAISSVIQEIYQQFDAIQANAQVDRLITGRLSSLSVLASAKQAEYIRVSQQRELATQKINECVKSQSIRYSFCGNGRHVLTIPQNAPNGIVFIHFSYTPDSFVNVTAIVGFCVKPANASQYAIVPANGRGIFIQVNGSYYITARDMYMPRAITAGDVVTLTSCQANYVSVNKTVITTFVDNDDFDFNDELSKWWNDTKHELPDFDKFNYTVPILDIDSEIDRIQGVIQGLNDSLIDLEKLSILKTYIKWPWYVWLAIAFATIIFILILGWVFFMTGCCGCCCGCFGIMPLMSKCGKKSSYYTTFDNDVVTEQYRPKKSV | 
| Enzyme Length | 1162 | 
| Uniprot Accession Number | P11223 | 
| Absorption | |
| Active Site | |
| Activity Regulation | |
| Binding Site | |
| Calcium Binding | |
| catalytic Activity | |
| DNA Binding | |
| EC Number | |
| Enzyme Function | FUNCTION: [Spike protein S1]: Attaches the virion to the host cell membrane by interacting with sialic acids, initiating the infection. {ECO:0000255|HAMAP-Rule:MF_04098, ECO:0000269|PubMed:16537586, ECO:0000269|PubMed:24314633}.; FUNCTION: [Spike protein S2]: Mediates fusion of the virion and cellular membranes by acting as a class I viral fusion protein. Under the current model, the protein has at least 3 conformational states: pre-fusion native state, pre-hairpin intermediate state, and post-fusion hairpin state. During viral and target cell membrane fusion, the coiled coil regions (heptad repeats) assume a trimer-of-hairpins structure, positioning the fusion peptide in close proximity to the C-terminal region of the ectodomain. The formation of this structure appears to drive apposition and subsequent fusion of viral and target cell membranes. {ECO:0000255|HAMAP-Rule:MF_04098}.; FUNCTION: [Spike protein S2']: Acts as a viral fusion peptide after S2 cleavage occurring upon virus endocytosis. {ECO:0000255|HAMAP-Rule:MF_04098}. | 
| Temperature Dependency | |
| PH Dependency | |
| Pathway | |
| nucleotide Binding | |
| Features | Chain (4); Coiled coil (2); Glycosylation (28); Motif (1); Mutagenesis (2); Natural variant (12); Region (2); Signal peptide (1); Site (2); Topological domain (2); Transmembrane (1) | 
| Keywords | Cleavage on pair of basic residues;Coiled coil;Fusion of virus membrane with host endosomal membrane;Fusion of virus membrane with host membrane;Glycoprotein;Host membrane;Host-virus interaction;Membrane;Reference proteome;Signal;Transmembrane;Transmembrane helix;Viral attachment to host cell;Viral envelope protein;Viral penetration into host cytoplasm;Virion;Virulence;Virus endocytosis by host;Virus entry into host cell | 
| Interact With | O00303 | 
| Induction | |
| Subcellular Location | SUBCELLULAR LOCATION: [Spike protein S2]: Virion membrane {ECO:0000255|HAMAP-Rule:MF_04098}; Single-pass type I membrane protein {ECO:0000255|HAMAP-Rule:MF_04098}. Host endoplasmic reticulum-Golgi intermediate compartment membrane {ECO:0000255|HAMAP-Rule:MF_04098}; Single-pass type I membrane protein {ECO:0000255|HAMAP-Rule:MF_04098}. Note=Accumulates in the endoplasmic reticulum-Golgi intermediate compartment, where it participates in virus particle assembly. Some S oligomers may be transported to the plasma membrane, where they may mediate cell-cell fusion. {ECO:0000255|HAMAP-Rule:MF_04098}.; SUBCELLULAR LOCATION: [Spike protein S1]: Virion membrane {ECO:0000255|HAMAP-Rule:MF_04098}; Peripheral membrane protein {ECO:0000255|HAMAP-Rule:MF_04098}. Host endoplasmic reticulum-Golgi intermediate compartment membrane {ECO:0000255|HAMAP-Rule:MF_04098}; Peripheral membrane protein {ECO:0000255|HAMAP-Rule:MF_04098}. Note=Accumulates in the endoplasmic reticulum-Golgi intermediate compartment, where it participates in virus particle assembly. Some S oligomers may be transported to the plasma membrane, where they may mediate cell-cell fusion. S1 is not anchored to the viral envelope, but associates with the extravirion surface through its binding to S2. {ECO:0000255|HAMAP-Rule:MF_04098}. | 
| Modified Residue | |
| Post Translational Modification | PTM: Specific enzymatic cleavages in vivo yield mature proteins. The precursor is processed into S1 and S2 by host cell furin or furin-like protease to yield the mature S1 and S2 proteins. The cleavage site between S1 and S2 requires the optimal sequence [KR]-X-[KR]-R. Additionally, a second cleavage leads to the release of a fusion peptide after viral attachment to host cell receptor. {ECO:0000255|HAMAP-Rule:MF_04098, ECO:0000269|PubMed:19553314}. | 
| Signal Peptide | SIGNAL 1..18; /evidence=ECO:0000255|HAMAP-Rule:MF_04098 | 
| Structure 3D | |
| Cross Reference PDB | - | 
| Mapped Pubmed ID | 15763735; 17043759; 18712588; 22017046; 22573006; 23896748; 24041648; 25055623; 29944406; 30021894; 31078931; | 
| Motif | MOTIF 1159..1162; /note=Di-lysine motif; /evidence=ECO:0000255|HAMAP-Rule:MF_04098 | 
| Gene Encoded By | |
| Mass | 128,047 | 
| Kinetics | |
| Metal Binding | |
| Rhea ID | |
| Cross Reference Brenda |