Entry
Name
complement subcomponent C_overbar_1s_;
C1 esterase;
activated complement C1s;
complement C_overbar_1r_
Class
Hydrolases;
Acting on peptide bonds (peptidases);
Serine endopeptidases
BRITE hierarchy
Reaction(IUBMB)
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
Comment
Activated from proenzyme C1s in plasma by complement subcomponent C_overbar_1r_. In peptidase family S1 (trypsin family)
History
EC 3.4.21.42 created 1981
Orthology
K01331 complement component 1, s subcomponent
Genes
PON : 100432027 100455685(C1S)
MCF : 102134687 102137207(C1S)
MTHB : 126930476 126930486
CSAB : 103218499 103218857(C1S)
PANU : 101003889(C1S) 101009560
RRO : 104664861 104680080(C1S)
PTEH : 111555895(C1S) 113222927 113222930 113222931
MMU : 317677(C1s2) 50908(C1s1)
MPAH : 110314998 110316909(C1s)
TUP : 102487452 102496444(C1S)
TST : 117885631(C1S) 117886664
MRV : 120370719 120395337(C1S)
ACS : 100558615(c1s) 100560720
CAUA : 113081686 113099592
MSAM : 119896349 119897430 119897431
RTP : 109914345(c1s) 109924983 109925885
CPLA : 122542919 122542923
LERI : 129716458 129716463
» show all
Taxonomy
Reference
Authors
Sim RB.
Title
The human complement system serine proteases C1r and C1s and their proenzymes.
Journal
Reference
Authors
Mackinnon CM, Carter PE, Smyth SJ, Dunbar B, Fothergill JE
Title
Molecular cloning of cDNA for human complement component C1s. The complete amino acid sequence.
Journal
Sequence
Reference
Authors
Muller-Eberhard HJ.
Title
Molecular organization and function of the complement system.
Journal
Reference
Authors
Skoog MT, Mehdi S, Wiseman JS, Bey P.
Title
The specificity of two proteinases that cleave adjacent to arginine, C1 esterase and acrosin, for peptide p-nitroanilide substrates.
Journal
Other DBs
ExPASy - ENZYME nomenclature database: 3.4.21.42