| IED ID | IndEnz0002000032 |
| Enzyme Type ID | protease000032 |
| Protein Name |
Complement C1s subcomponent EC 3.4.21.42 C1 esterase Complement component 1 subcomponent s Cleaved into: Complement C1s subcomponent heavy chain; Complement C1s subcomponent light chain |
| Gene Name | C1S |
| Organism | Homo sapiens (Human) |
| Taxonomic Lineage | cellular organisms Eukaryota Opisthokonta Metazoa Eumetazoa Bilateria Deuterostomia Chordata Craniata Vertebrata Gnathostomata (jawed vertebrates) Teleostomi Euteleostomi Sarcopterygii Dipnotetrapodomorpha Tetrapoda Amniota Mammalia Theria Eutheria Boreoeutheria Euarchontoglires Primates Haplorrhini Simiiformes Catarrhini Hominoidea (apes) Hominidae (great apes) Homininae Homo Homo sapiens (Human) |
| Enzyme Sequence | MWCIVLFSLLAWVYAEPTMYGEILSPNYPQAYPSEVEKSWDIEVPEGYGIHLYFTHLDIELSENCAYDSVQIISGDTEEGRLCGQRSSNNPHSPIVEEFQVPYNKLQVIFKSDFSNEERFTGFAAYYVATDINECTDFVDVPCSHFCNNFIGGYFCSCPPEYFLHDDMKNCGVNCSGDVFTALIGEIASPNYPKPYPENSRCEYQIRLEKGFQVVVTLRREDFDVEAADSAGNCLDSLVFVAGDRQFGPYCGHGFPGPLNIETKSNALDIIFQTDLTGQKKGWKLRYHGDPMPCPKEDTPNSVWEPAKAKYVFRDVVQITCLDGFEVVEGRVGATSFYSTCQSNGKWSNSKLKCQPVDCGIPESIENGKVEDPESTLFGSVIRYTCEEPYYYMENGGGGEYHCAGNGSWVNEVLGPELPKCVPVCGVPREPFEEKQRIIGGSDADIKNFPWQVFFDNPWAGGALINEYWVLTAAHVVEGNREPTMYVGSTSVQTSRLAKSKMLTPEHVFIHPGWKLLEVPEGRTNFDNDIALVRLKDPVKMGPTVSPICLPGTSSDYNLMDGDLGLISGWGRTEKRDRAVRLKAARLPVAPLRKCKEVKVEKPTADAEAYVFTPNMICAGGEKGMDSCKGDSGGAFAVQDPNDKTKFYAAGLVSWGPQCGTYGLYTRVKNYVDWIMKTMQENSTPRED |
| Enzyme Length | 688 |
| Uniprot Accession Number | P09871 |
| Absorption | |
| Active Site | ACT_SITE 475; /note=Charge relay system; ACT_SITE 529; /note=Charge relay system; ACT_SITE 632; /note=Charge relay system |
| Activity Regulation | ACTIVITY REGULATION: Inhibited by SERPING1. {ECO:0000269|PubMed:11527969}. |
| Binding Site | |
| Calcium Binding | |
| catalytic Activity | CATALYTIC ACTIVITY: Reaction=Cleavage of Arg-|-Ala bond in complement component C4 to form C4a and C4b, and Lys(or Arg)-|-Lys bond in complement component C2 to form C2a and C2b: the 'classical' pathway C3 convertase.; EC=3.4.21.42; Evidence={ECO:0000269|PubMed:11527969}; |
| DNA Binding | |
| EC Number | 3.4.21.42 |
| Enzyme Function | FUNCTION: C1s B chain is a serine protease that combines with C1q and C1r to form C1, the first component of the classical pathway of the complement system. C1r activates C1s so that it can, in turn, activate C2 and C4. |
| Temperature Dependency | |
| PH Dependency | |
| Pathway | |
| nucleotide Binding | |
| Features | Active site (3); Beta strand (51); Chain (3); Disulfide bond (13); Domain (6); Glycosylation (2); Helix (11); Metal binding (9); Modified residue (1); Natural variant (5); Sequence conflict (4); Signal peptide (1); Turn (8) |
| Keywords | 3D-structure;Calcium;Complement pathway;Direct protein sequencing;Disease variant;Disulfide bond;EGF-like domain;Ehlers-Danlos syndrome;Glycoprotein;Hydrolase;Hydroxylation;Immunity;Innate immunity;Metal-binding;Protease;Reference proteome;Repeat;Serine protease;Signal;Sushi |
| Interact With | P00736; Itself; O43889-2; Q9H6H4 |
| Induction | |
| Subcellular Location | |
| Modified Residue | MOD_RES 149; /note=(3R)-3-hydroxyasparagine; /evidence=ECO:0000269|PubMed:2141278 |
| Post Translational Modification | PTM: The iron and 2-oxoglutarate dependent 3-hydroxylation of aspartate and asparagine is (R) stereospecific within EGF domains. {ECO:0000269|PubMed:2141278}. |
| Signal Peptide | SIGNAL 1..15; /evidence=ECO:0000269|PubMed:3007145 |
| Structure 3D | X-ray crystallography (9) |
| Cross Reference PDB | 1ELV; 1NZI; 4J1Y; 4LMF; 4LOR; 4LOS; 4LOT; 6F1C; 6F1H; |
| Mapped Pubmed ID | 10925294; 12396008; 1249422; 14280442; 14674770; 15199963; 1533159; 16169853; 17996945; 18062908; 19344414; 19423540; 20008834; 20406964; 20438785; 20467438; 20592021; 20711500; 22855709; 23300094; 23592783; 23650384; 2387866; 23922389; 23989031; 24695853; 26231209; 28104818; 29311313; 31921203; 33804666; 34155115; 6019133; 70787; 760802; 761607; 814163; |
| Motif | |
| Gene Encoded By | |
| Mass | 76,684 |
| Kinetics | BIOPHYSICOCHEMICAL PROPERTIES: Kinetic parameters: KM=12.3 uM for complement component C2 (at 37 degrees Celsius) {ECO:0000269|PubMed:11527969}; KM=1.9 uM for complement component C4 (at 37 degrees Celsius) {ECO:0000269|PubMed:11527969}; Note=Less efficient than MASP2 in C4 cleavage.; |
| Metal Binding | METAL 60; /note=Calcium; METAL 68; /note=Calcium; METAL 113; /note=Calcium; METAL 131; /note=Calcium; METAL 132; /note=Calcium; via carbonyl oxygen; METAL 134; /note=Calcium; METAL 149; /note=Calcium; METAL 150; /note=Calcium; via carbonyl oxygen; METAL 153; /note=Calcium; via carbonyl oxygen |
| Rhea ID | |
| Cross Reference Brenda | 3.4.21.42; |