The name of this superfamily has been modified since the most recent official CATH+ release (v4_3_0). At the point of the last release, this superfamily was named:

Complement Module, domain 1

Functional Families

Overview of the Structural Clusters (SC) and Functional Families within this CATH Superfamily. Clusters with a representative structure are represented by a filled circle.
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FunFam 16: Mannan-binding lectin serine protease 1

There are 3 EC terms in this cluster

Please note: EC annotations are assigned to the full protein sequence rather than individual protein domains. Since a given protein can contain multiple domains, it is possible that some of the annotations below come from additional domains that occur in the same protein, but have been classified elsewhere in CATH.

Note: The search results have been sorted with the annotations that are found most frequently at the top of the list. The results can be filtered by typing text into the search box at the top of the table.

EC Term Annotations Evidence
Complement subcomponent C1r. [EC:]
Selective cleavage of Lys(or Arg)-|-Ile bond in complement subcomponent C1s to form the active form of C1s (EC
  • Activates C1s by proteolytic cleavage so that it can, in turn, activate C2 and C4.
  • Activated from proenzyme C1r in plasma by autocatalytic mechanism during activation of the complement system by the 'classical' route.
  • Belongs to peptidase family S1.
6 P00736 Q4R577 Q5R1W3 Q5R544 Q8CFG9 Q8CG16
Complement subcomponent C1s. [EC:]
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.
  • Activated from proenzyme C1s in plasma by the activated complement subcomponent C1r.
  • Belongs to peptidase family S1.
6 P09871 Q0VCX1 Q69DK8 Q6P6T1 Q8CFG8 Q8CG14
Mannan-binding lectin-associated serine protease-2. [EC:]
Selective cleavage after Arg-223 in complement component C2 (-Ser- Leu-Gly-Arg-|-Lys-Ile-Gln-Ile) and after Arg-76 in complement component C4 (-Gly-Leu-Gln-Arg-|-Ala-Leu-Glu-Ile).
  • Mannan-binding lectin (MBL) recognizes patterns of neutral carbohydrates, such as mannose and N-acetylglucosamine, on a wide range of microbial surfaces and is able to initiate activation of the lectin pathway of complement.
  • Displays C1s-like esterolytic activity (cf. EC
  • It also cleaves C4 and C2 with efficiencies that are relatively higher than those of EC
  • Belongs to peptidase family S1A.
3 O00187 Q91WP0 Q9JJS8