CATH Classification

Domain Context

CATH Clusters

Superfamily von Willebrand factor, type A domain
Functional Family Complement factor B

Enzyme Information

3.4.21.47
Alternative-complement-pathway C3/C5 convertase.
based on mapping to UniProt P00751
Cleavage of Arg-|-Ser bond in complement component C3 alpha-chain to yield C3a and C3b, and Arg-|-Xaa bond in complement component C5 alpha- chain to yield C5a and C5b.
-!- A bimolecular complex of complement fragment Bb with either C3b or cobra venom factor; Bb contains the active site. -!- Bb is formed by cleavage of proenzyme factor B by factor D. -!- Cleavage of complement component C5 requires additional C3b which binds C5 and renders it susceptible to cleavage by C3b,Bb complex. -!- C3b,Bb is stabilized in plasma by factor P. -!- Belongs to peptidase family S1.

UniProtKB Entries (1)

P00751
CFAB_HUMAN
Homo sapiens
Complement factor B

PDB Structure

PDB 1RS0
External Links
Method X-RAY DIFFRACTION
Organism Trichoplusia
Primary Citation
Structural analysis of engineered Bb fragment of complement factor B: insights into the activation mechanism of the alternative pathway C3-convertase.
Ponnuraj, K., Xu, Y., Macon, K., Moore, D., Volanakis, J.E., Narayana, S.V.
Mol.Cell