#ID(s) interactor A	ID(s) interactor B	Alt. ID(s) interactor A	Alt. ID(s) interactor B	Alias(es) interactor A	Alias(es) interactor B	Interaction detection method(s)	Publication 1st author(s)	Publication Identifier(s)	Taxid interactor A	Taxid interactor B	Interaction type(s)	Source database(s)	Interaction identifier(s)	Confidence value(s)	Expansion method(s)	Biological role(s) interactor A	Biological role(s) interactor B	Experimental role(s) interactor A	Experimental role(s) interactor B	Type(s) interactor A	Type(s) interactor B	Xref(s) interactor A	Xref(s) interactor B	Interaction Xref(s)	Annotation(s) interactor A	Annotation(s) interactor B	Interaction annotation(s)	Host organism(s)	Interaction parameter(s)	Creation date	Update date	Checksum(s) interactor A	Checksum(s) interactor B	Interaction Checksum(s)	Negative	Feature(s) interactor A	Feature(s) interactor B	Stoichiometry(s) interactor A	Stoichiometry(s) interactor B	Identification method participant A	Identification method participant B
uniprotkb:P27918	uniprotkb:P02741-PRO_0000023526	intact:EBI-9038570|uniprotkb:O15134|uniprotkb:O15135|uniprotkb:O15136|uniprotkb:O75826|ensembl:ENSP00000247153|ensembl:ENSP00000380189	intact:EBI-22033103	psi-mi:prop_human(display_long)|uniprotkb:CFP(gene name)|psi-mi:CFP(display_short)|uniprotkb:PFC(gene name synonym)|uniprotkb:Complement factor P(gene name synonym)	psi-mi:p02741-pro_0000023526(display_long)|uniprotkb:CRP(gene name)|psi-mi:CRP(display_short)|uniprotkb:PTX1(gene name synonym)	psi-mi:"MI:0411"(enzyme linked immunosorbent assay)	O'Flynn et al. (2016)	pubmed:26984957|imex:IM-27357	taxid:9606(human)|taxid:9606(Homo sapiens)	taxid:9606(human)|taxid:9606(Homo sapiens)	psi-mi:"MI:0407"(direct interaction)	psi-mi:"MI:0469"(IntAct)	intact:EBI-22033081|imex:IM-27357-1	-	-	psi-mi:"MI:0499"(unspecified role)	psi-mi:"MI:0499"(unspecified role)	psi-mi:"MI:0498"(prey)	psi-mi:"MI:0496"(bait)	psi-mi:"MI:0326"(protein)	psi-mi:"MI:0326"(protein)	refseq:NP_001138724.1|refseq:NP_002612.1|ensembl:ENSG00000126759(gene)|ensembl:ENST00000247153(transcript)|ensembl:ENST00000396992(transcript)|go:"GO:0005576"(extracellular region)|go:"GO:0005615"(extracellular space)|go:"GO:0005788"(endoplasmic reticulum lumen)|go:"GO:0006955"(immune response)|go:"GO:0006957"(complement activation, alternative pathway)|go:"GO:0035580"(specific granule lumen)|go:"GO:0042742"(defense response to bacterium)|go:"GO:1904724"(tertiary granule lumen)|interpro:IPR000884(Thrombospondin, type I)|interpro:IPR036383|rcsb pdb:1W0R|rcsb pdb:1W0S|rcsb pdb:6RUR|rcsb pdb:6RUS|rcsb pdb:6RUV|rcsb pdb:6RV6|rcsb pdb:6S08|rcsb pdb:6S0A|rcsb pdb:6S0B|rcsb pdb:6SEJ|reactome:R-HSA-173736|reactome:R-HSA-174577|reactome:R-HSA-5083635|reactome:R-HSA-5173214|reactome:R-HSA-6798695|reactome:R-HSA-977606	intact:EBI-1395983(chain-parent)	-	-	chain-seq-start:19|chain-seq-end:224	figure legend:3A|full coverage:Only protein-protein interactions|curation depth:imex curation	taxid:-1(in vitro)|taxid:-1(In vitro)	-	2019/09/04	2019/09/20	rogid:XBExMxbnkfjvnV9zHMRZgxZWKaw9606	rogid:CvK4vTdUxXgEsFN2HKUWzPg5lx49606	rigid:MakDcZ0wpFyeaSM29RgeLuBgWf4	false	-	protein modification:1-1|mutation:36-36,97-97	-	1	psi-mi:"MI:0421"(identification by antibody)	psi-mi:"MI:0421"(identification by antibody)
uniprotkb:P02741-PRO_0000023526	matrixdb:MULT_84_human	intact:EBI-22033103	intact:EBI-12735745|wwpdb:5fo7|wwpdb:3g6j|wwpdb:2i07|reactome:R-HSA-166832	psi-mi:p02741-pro_0000023526(display_long)|uniprotkb:CRP(gene name)|psi-mi:CRP(display_short)|uniprotkb:PTX1(gene name synonym)	psi-mi:c3b_human(display_short)|psi-mi:MULT_84_human(display_long)|intact:Complement C3b complex(complex recommended name)|intact:C3b dimer(complex systematic name)	psi-mi:"MI:0411"(enzyme linked immunosorbent assay)	O'Flynn et al. (2016)	pubmed:26984957|imex:IM-27357	taxid:9606(human)|taxid:9606(Homo sapiens)	taxid:9606(human)|taxid:9606(Homo sapiens)	psi-mi:"MI:0915"(physical association)	psi-mi:"MI:0469"(IntAct)	intact:EBI-22033480|imex:IM-27357-3	-	psi-mi:"MI:1060"(spoke expansion)	psi-mi:"MI:0499"(unspecified role)	psi-mi:"MI:0499"(unspecified role)	psi-mi:"MI:0496"(bait)	psi-mi:"MI:0498"(prey)	psi-mi:"MI:0326"(protein)	psi-mi:"MI:1302"(stable complex)	intact:EBI-1395983(chain-parent)	pubmed:27782329(see-also)|pubmed:6225800(see-also)|evidence ontology:"ECO:0000353"|efo:"Orphanet:280133"(see-also)|efo:"Orphanet:2134"(see-also)|efo:"Orphanet:93575"(see-also)|efo:"EFO:0001365"(see-also)|pubmed:27013439(see-also)|pubmed:19196712(see-also)|pubmed:17051160(see-also)|go:"GO:0005615"(extracellular space)|go:"GO:0001848"(complement binding)|go:"GO:1903028"(positive regulation of opsonization)|go:"GO:0006956"(complement activation)|go:"GO:0050766"(positive regulation of phagocytosis)|go:"GO:0044533"(positive regulation of apoptotic process in another organism)|go:"GO:0050778"(positive regulation of immune response)|go:"GO:0030449"(regulation of complement activation)|go:"GO:0008228"(opsonization)|pubmed:6559201(see-also)|pubmed:15454921(see-also)|pubmed:21205667(see-also)|pubmed:17051150(see-also)|complex portal:CPX-973(complex-primary)|pubmed:26489954(see-also)	-	chain-seq-start:19|chain-seq-end:224	curated-complex:"A protein complex of the alternative pathway of complement activation of the innate immune system. Complement C3 precurser is activated by cleavage into C3a and C3b by C3 convertases, either C4bC2a in the classical and lectin pathways or C3(H2O)Bb, C3bBb, C3bBbC3b, C3bBbP or C3bBbC3bP in the alternative pathway.     C3b acts as an opsonin and interacts with glycoproteins and carbohydrates on pathogenic or apoptotic target cell surfaces through its reactive thioester moiety. Opsonization of target cells leads to enhanced phagocytosis, lysis of target cells via membrane attack complex (CPX-6159) assembly, clearance of antibody-antigen complexes and up-regulation of the adaptive response.     Activation of C3b leads to an amplification cascade that generates more C3 convertase, deposits more C3b at the local site and switches C3 convertases to C5 convertases.     To protect host cells from inadvertent complement activation the activation of C3b is tightly regulated by either disrupting the C3 convertases or aiding in the proteolytic degradation of C3b. Bacteria and viruses possess C3b proteases to evade the complement response.     Lack of protection, due to familial mutations in the complement genes or the presence of autoantibodies against regulators has been linked to atypical hemolytic uremic syndrome (aHUS) and C3 glomerulopathies (C3G) in kidneys and age-related macular degeneration (AMD) in eyes. Conditions of chronic and acute inflammations, as in rheumatoid arthritis, strokes, and heart attacks, become aggravated by complement activation against the disturbed tissue."|complex-properties:"The alternative pathway is continuously activated at a low level. C3 precursor is first processed by the removal of 4 Arg residues and spontaneous hydrolysis due to the breakdown of the internal thioester bond forms C3(H2O) (disulfide bonded P01024-PRO_0000005909 & P01024-PRO_0000005908).     C3(H2O) subsequently binds factor B that is cleaved by Factor D (P00746) into 2 fragments: CFBa and CFBb. CFBb, a serine protease, then combines with complement factor C3(H2O) or C3b to generate the C3 or C5 convertases.     Proteolytic cleavage of C3 to C3b is accompanied by large conformational changes that result in the exposure of cryptic binding sites required for convertase assembly and regulation. This includes a significant movement of the thioester-bond-containing domain through which C3b attaches to target surfaces."|complex-assembly:Heterodimer|disease:"Complement component 3 (C3) deficiency [Orphanet:280133]: a rare, autosomal recessive defect of the complement classical pathway. Patients develop recurrent, severe, pyogenic infections because of ineffective opsonization of pathogens. Some patients may also develop autoimmune disorders, such as arthralgia and vasculitic rashes, lupus-like syndrome and membranoproliferative glomerulonephritis."|disease:"Atypical hemolytic-uremic syndrome with C3 anomaly [Orphanet:2134 & Orphanet:93575]: an autosomal dominant, atypical form of hemolytic-uremic syndrome (aHUS, a thrombotic microangiopathy) characterized by mechanical hemolytic anemia, thrombocytopenia, and renal dysfunction."|disease:"Age-related macular degeneration [EFO:0001365]: age-related macular degeneration usually in older adults which results in a loss of vision in the center of the visual field (the macula lutea) because of damage to the retina. Manifests as ophthalmoscopically visible yellowish accumulations of protein and lipid that lie beneath the retinal pigment epithelium and within an elastin-containing structure known as Bruch membrane. Occurs in dry and wet forms. Most common cause of irreversible vision loss in the developed world."	figure legend:3B|full coverage:Only protein-protein interactions|curation depth:imex curation	taxid:-1(in vitro)|taxid:-1(In vitro)	-	2019/09/04	2019/10/06	rogid:CvK4vTdUxXgEsFN2HKUWzPg5lx49606	-	-	false	protein modification:1-1|mutation:36-36,97-97	-	1	-	psi-mi:"MI:0421"(identification by antibody)	psi-mi:"MI:0421"(identification by antibody)
uniprotkb:P02741-PRO_0000023526	uniprotkb:P27918	intact:EBI-22033103	intact:EBI-9038570|uniprotkb:O15134|uniprotkb:O15135|uniprotkb:O15136|uniprotkb:O75826|ensembl:ENSP00000247153|ensembl:ENSP00000380189	psi-mi:p02741-pro_0000023526(display_long)|uniprotkb:CRP(gene name)|psi-mi:CRP(display_short)|uniprotkb:PTX1(gene name synonym)	psi-mi:prop_human(display_long)|uniprotkb:CFP(gene name)|psi-mi:CFP(display_short)|uniprotkb:PFC(gene name synonym)|uniprotkb:Complement factor P(gene name synonym)	psi-mi:"MI:0411"(enzyme linked immunosorbent assay)	O'Flynn et al. (2016)	pubmed:26984957|imex:IM-27357	taxid:9606(human)|taxid:9606(Homo sapiens)	taxid:9606(human)|taxid:9606(Homo sapiens)	psi-mi:"MI:0915"(physical association)	psi-mi:"MI:0469"(IntAct)	intact:EBI-22033480|imex:IM-27357-3	-	psi-mi:"MI:1060"(spoke expansion)	psi-mi:"MI:0499"(unspecified role)	psi-mi:"MI:0499"(unspecified role)	psi-mi:"MI:0496"(bait)	psi-mi:"MI:0684"(ancillary)	psi-mi:"MI:0326"(protein)	psi-mi:"MI:0326"(protein)	intact:EBI-1395983(chain-parent)	refseq:NP_001138724.1|refseq:NP_002612.1|ensembl:ENSG00000126759(gene)|ensembl:ENST00000247153(transcript)|ensembl:ENST00000396992(transcript)|go:"GO:0005576"(extracellular region)|go:"GO:0005615"(extracellular space)|go:"GO:0005788"(endoplasmic reticulum lumen)|go:"GO:0006955"(immune response)|go:"GO:0006957"(complement activation, alternative pathway)|go:"GO:0035580"(specific granule lumen)|go:"GO:0042742"(defense response to bacterium)|go:"GO:1904724"(tertiary granule lumen)|interpro:IPR000884(Thrombospondin, type I)|interpro:IPR036383|rcsb pdb:1W0R|rcsb pdb:1W0S|rcsb pdb:6RUR|rcsb pdb:6RUS|rcsb pdb:6RUV|rcsb pdb:6RV6|rcsb pdb:6S08|rcsb pdb:6S0A|rcsb pdb:6S0B|rcsb pdb:6SEJ|reactome:R-HSA-173736|reactome:R-HSA-174577|reactome:R-HSA-5083635|reactome:R-HSA-5173214|reactome:R-HSA-6798695|reactome:R-HSA-977606	-	chain-seq-start:19|chain-seq-end:224	-	figure legend:3B|full coverage:Only protein-protein interactions|curation depth:imex curation	taxid:-1(in vitro)|taxid:-1(In vitro)	-	2019/09/04	2019/10/06	rogid:CvK4vTdUxXgEsFN2HKUWzPg5lx49606	rogid:XBExMxbnkfjvnV9zHMRZgxZWKaw9606	-	false	protein modification:1-1|mutation:36-36,97-97	-	1	-	psi-mi:"MI:0421"(identification by antibody)	psi-mi:"MI:0421"(identification by antibody)