Q61129 · CFAI_MOUSE
- ProteinComplement factor I
- GeneCfi
- StatusUniProtKB reviewed (Swiss-Prot)
- Organism
- Amino acids603 (go to sequence)
- Protein existenceEvidence at protein level
- Annotation score5/5
Function
function
Trypsin-like serine protease that plays an essential role in regulating the immune response by controlling all complement pathways. Inhibits these pathways by cleaving three peptide bonds in the alpha-chain of C3b and two bonds in the alpha-chain of C4b thereby inactivating these proteins. Essential cofactors for these reactions include factor H and C4BP in the fluid phase and membrane cofactor protein/CD46 and CR1 on cell surfaces. The presence of these cofactors on healthy cells allows degradation of deposited C3b by CFI in order to prevent undesired complement activation, while in apoptotic cells or microbes, the absence of such cofactors leads to C3b-mediated complement activation and subsequent opsonization.
Catalytic activity
Features
Showing features for binding site, active site.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Binding site | 244 | Ca2+ 1 (UniProtKB | ChEBI) | ||||
Sequence: K | ||||||
Binding site | 247 | Ca2+ 1 (UniProtKB | ChEBI) | ||||
Sequence: N | ||||||
Binding site | 249 | Ca2+ 1 (UniProtKB | ChEBI) | ||||
Sequence: V | ||||||
Binding site | 251 | Ca2+ 1 (UniProtKB | ChEBI) | ||||
Sequence: D | ||||||
Binding site | 257 | Ca2+ 1 (UniProtKB | ChEBI) | ||||
Sequence: D | ||||||
Binding site | 258 | Ca2+ 1 (UniProtKB | ChEBI) | ||||
Sequence: E | ||||||
Binding site | 281 | Ca2+ 2 (UniProtKB | ChEBI) | ||||
Sequence: Y | ||||||
Binding site | 284 | Ca2+ 2 (UniProtKB | ChEBI) | ||||
Sequence: N | ||||||
Binding site | 286 | Ca2+ 2 (UniProtKB | ChEBI) | ||||
Sequence: E | ||||||
Binding site | 288 | Ca2+ 2 (UniProtKB | ChEBI) | ||||
Sequence: D | ||||||
Binding site | 294 | Ca2+ 2 (UniProtKB | ChEBI) | ||||
Sequence: D | ||||||
Binding site | 295 | Ca2+ 2 (UniProtKB | ChEBI) | ||||
Sequence: E | ||||||
Active site | 401 | Charge relay system | ||||
Sequence: H | ||||||
Active site | 449 | Charge relay system | ||||
Sequence: D | ||||||
Active site | 545 | Charge relay system | ||||
Sequence: S |
GO annotations
Aspect | Term | |
---|---|---|
Cellular Component | extracellular space | |
Cellular Component | membrane | |
Molecular Function | metal ion binding | |
Molecular Function | serine-type endopeptidase activity | |
Biological Process | complement activation | |
Biological Process | complement activation, classical pathway | |
Biological Process | innate immune response | |
Biological Process | proteolysis |
Keywords
- Molecular function
- Biological process
- Ligand
Enzyme and pathway databases
Protein family/group databases
Names & Taxonomy
Protein names
- Recommended nameComplement factor I
- EC number
- Alternative names
- Cleaved into 2 chains
Gene names
Organism names
- Organism
- Strains
- Taxonomic lineageEukaryota > Metazoa > Chordata > Craniata > Vertebrata > Euteleostomi > Mammalia > Eutheria > Euarchontoglires > Glires > Rodentia > Myomorpha > Muroidea > Muridae > Murinae > Mus > Mus
Accessions
- Primary accessionQ61129
- Secondary accessions
Proteomes
Organism-specific databases
Subcellular Location
Phenotypes & Variants
Disruption phenotype
CFI-deficient mice are viable and fertile under specific pathogen-free conditions. In the absence of factor I/CFI, physiological cleavage of the alpha-chain of C3b is prevented, and reduced plasma C3, factor B, and factor H levels are observed.
Variants
We now provide the "Disease & Variants" viewer in its own tab.
The viewer provides 40 variants from UniProt as well as other sources including ClinVar and dbSNP.
PTM/Processing
Features
Showing features for signal, chain, disulfide bond, glycosylation.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Signal | 1-18 | |||||
Sequence: MKLAHLSLFLLALHLSSS | ||||||
Chain | PRO_0000027572 | 19-356 | Complement factor I heavy chain | |||
Sequence: RSPSASDLPQEELVDQKCLLQKYTHRSCNKVFCQPWQRCIEGTCICKLPYQCPRAGTPVCAMNGRSYPTYCHQKSFECLHPEIKFSHNGTCAAEGKFNVSLIYGRTKTEGLVQVKLVDQDERMFICKNSWSMAEANVACVDLGFPLGVRDIQGSFNISGNLHINDTECLHVHCRGVETSLAECAFTKRRTELSNGLAGVVCYKQDADFPTSLSFQCVNGKHIPQEKACNGVNDCGDQSDELCCKGCRGNASLCKSGVCIPDQYKCNGEVDCITGEDESRCEEDRQQNIPKGLARSAQGEAEIETEETEMLTPGMDNERKRIKSLLPKLSCGVKRNTHT | ||||||
Chain | PRO_0000027571 | 19-603 | Complement factor I | |||
Sequence: RSPSASDLPQEELVDQKCLLQKYTHRSCNKVFCQPWQRCIEGTCICKLPYQCPRAGTPVCAMNGRSYPTYCHQKSFECLHPEIKFSHNGTCAAEGKFNVSLIYGRTKTEGLVQVKLVDQDERMFICKNSWSMAEANVACVDLGFPLGVRDIQGSFNISGNLHINDTECLHVHCRGVETSLAECAFTKRRTELSNGLAGVVCYKQDADFPTSLSFQCVNGKHIPQEKACNGVNDCGDQSDELCCKGCRGNASLCKSGVCIPDQYKCNGEVDCITGEDESRCEEDRQQNIPKGLARSAQGEAEIETEETEMLTPGMDNERKRIKSLLPKLSCGVKRNTHTRRKRVIGGKPANVGDYPWQVAIKDGQRITCGGIYIGGCWILTAAHCVRPSRAHSYQVWTALLDWLKPNSQLGIQTVKRVIVHEKYNGATFQNDIALIEMKMHTGKKECELPNSVPACVPWSPYLFQPNDRCIISGWGRGKDNQKVYSLRWGEVDLIGNCSQFYPDRYYEKEMQCAGTRDGSIDACKGDSGGPLVCEDINNVTYVWGIVSWGENCGKPEFPGVYTRVANYFDWISYHVGRSLVSQHNV | ||||||
Disulfide bond | 36↔260 | |||||
Sequence: CLLQKYTHRSCNKVFCQPWQRCIEGTCICKLPYQCPRAGTPVCAMNGRSYPTYCHQKSFECLHPEIKFSHNGTCAAEGKFNVSLIYGRTKTEGLVQVKLVDQDERMFICKNSWSMAEANVACVDLGFPLGVRDIQGSFNISGNLHINDTECLHVHCRGVETSLAECAFTKRRTELSNGLAGVVCYKQDADFPTSLSFQCVNGKHIPQEKACNGVNDCGDQSDELC | ||||||
Disulfide bond | 46↔57 | |||||
Sequence: CNKVFCQPWQRC | ||||||
Disulfide bond | 51↔62 | |||||
Sequence: CQPWQRCIEGTC | ||||||
Disulfide bond | 64↔96 | |||||
Sequence: CKLPYQCPRAGTPVCAMNGRSYPTYCHQKSFEC | ||||||
Disulfide bond | 70↔89 | |||||
Sequence: CPRAGTPVCAMNGRSYPTYC | ||||||
Disulfide bond | 78↔109 | |||||
Sequence: CAMNGRSYPTYCHQKSFECLHPEIKFSHNGTC | ||||||
Glycosylation | 106 | N-linked (GlcNAc...) asparagine | ||||
Sequence: N | ||||||
Glycosylation | 116 | N-linked (GlcNAc...) asparagine | ||||
Sequence: N | ||||||
Disulfide bond | 144↔186 | |||||
Sequence: CKNSWSMAEANVACVDLGFPLGVRDIQGSFNISGNLHINDTEC | ||||||
Disulfide bond | 157↔219 | |||||
Sequence: CVDLGFPLGVRDIQGSFNISGNLHINDTECLHVHCRGVETSLAECAFTKRRTELSNGLAGVVC | ||||||
Glycosylation | 174 | N-linked (GlcNAc...) asparagine | ||||
Sequence: N | ||||||
Glycosylation | 182 | N-linked (GlcNAc...) asparagine | ||||
Sequence: N | ||||||
Disulfide bond | 191↔201 | |||||
Sequence: CRGVETSLAEC | ||||||
Disulfide bond | 234↔252 | |||||
Sequence: CVNGKHIPQEKACNGVNDC | ||||||
Disulfide bond | 246↔261 | |||||
Sequence: CNGVNDCGDQSDELCC | ||||||
Disulfide bond | 264↔276 | |||||
Sequence: CRGNASLCKSGVC | ||||||
Glycosylation | 267 | N-linked (GlcNAc...) asparagine | ||||
Sequence: N | ||||||
Disulfide bond | 271↔289 | |||||
Sequence: CKSGVCIPDQYKCNGEVDC | ||||||
Disulfide bond | 283↔298 | |||||
Sequence: CNGEVDCITGEDESRC | ||||||
Disulfide bond | 348↔473 | Interchain (between heavy and light chains) | ||||
Sequence: CGVKRNTHTRRKRVIGGKPANVGDYPWQVAIKDGQRITCGGIYIGGCWILTAAHCVRPSRAHSYQVWTALLDWLKPNSQLGIQTVKRVIVHEKYNGATFQNDIALIEMKMHTGKKECELPNSVPAC | ||||||
Chain | PRO_0000027573 | 361-603 | Complement factor I light chain | |||
Sequence: VIGGKPANVGDYPWQVAIKDGQRITCGGIYIGGCWILTAAHCVRPSRAHSYQVWTALLDWLKPNSQLGIQTVKRVIVHEKYNGATFQNDIALIEMKMHTGKKECELPNSVPACVPWSPYLFQPNDRCIISGWGRGKDNQKVYSLRWGEVDLIGNCSQFYPDRYYEKEMQCAGTRDGSIDACKGDSGGPLVCEDINNVTYVWGIVSWGENCGKPEFPGVYTRVANYFDWISYHVGRSLVSQHNV | ||||||
Disulfide bond | 386↔402 | |||||
Sequence: CGGIYIGGCWILTAAHC | ||||||
Disulfide bond | 394↔464 | |||||
Sequence: CWILTAAHCVRPSRAHSYQVWTALLDWLKPNSQLGIQTVKRVIVHEKYNGATFQNDIALIEMKMHTGKKEC | ||||||
Disulfide bond | 473 | Interchain (with C-327) | ||||
Sequence: C | ||||||
Disulfide bond | 487↔551 | |||||
Sequence: CIISGWGRGKDNQKVYSLRWGEVDLIGNCSQFYPDRYYEKEMQCAGTRDGSIDACKGDSGGPLVC | ||||||
Glycosylation | 514 | N-linked (GlcNAc...) asparagine | ||||
Sequence: N | ||||||
Disulfide bond | 515↔530 | |||||
Sequence: CSQFYPDRYYEKEMQC | ||||||
Disulfide bond | 541↔570 | |||||
Sequence: CKGDSGGPLVCEDINNVTYVWGIVSWGENC | ||||||
Glycosylation | 556 | N-linked (GlcNAc...) asparagine | ||||
Sequence: N |
Keywords
- PTM
Proteomic databases
PTM databases
Expression
Tissue specificity
Expressed in the liver by hepatocytes. Also present in other cells such as monocytes, fibroblasts or keratinocytes.
Gene expression databases
Interaction
Subunit
Heterodimer of a light and heavy chains; disulfide-linked. The fully processed and mature protein circulates as a zymogen, and is allosterically activated by substrate-induced remodeling of the active site. Interacts with C3b. Interacts with complement factor H.
Protein-protein interaction databases
Miscellaneous
Structure
Family & Domains
Features
Showing features for domain.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Domain | 58-111 | Kazal-like | ||||
Sequence: IEGTCICKLPYQCPRAGTPVCAMNGRSYPTYCHQKSFECLHPEIKFSHNGTCAA | ||||||
Domain | 117-217 | SRCR | ||||
Sequence: VSLIYGRTKTEGLVQVKLVDQDERMFICKNSWSMAEANVACVDLGFPLGVRDIQGSFNISGNLHINDTECLHVHCRGVETSLAECAFTKRRTELSNGLAGV | ||||||
Domain | 218-262 | LDL-receptor class A 1 | ||||
Sequence: VCYKQDADFPTSLSFQCVNGKHIPQEKACNGVNDCGDQSDELCCK | ||||||
Domain | 263-299 | LDL-receptor class A 2 | ||||
Sequence: GCRGNASLCKSGVCIPDQYKCNGEVDCITGEDESRCE | ||||||
Domain | 361-594 | Peptidase S1 | ||||
Sequence: VIGGKPANVGDYPWQVAIKDGQRITCGGIYIGGCWILTAAHCVRPSRAHSYQVWTALLDWLKPNSQLGIQTVKRVIVHEKYNGATFQNDIALIEMKMHTGKKECELPNSVPACVPWSPYLFQPNDRCIISGWGRGKDNQKVYSLRWGEVDLIGNCSQFYPDRYYEKEMQCAGTRDGSIDACKGDSGGPLVCEDINNVTYVWGIVSWGENCGKPEFPGVYTRVANYFDWISYHVG |
Sequence similarities
Belongs to the peptidase S1 family.
Keywords
- Domain
Phylogenomic databases
Family and domain databases
Sequence
- Sequence statusComplete
- Sequence processingThe displayed sequence is further processed into a mature form.
- Length603
- Mass (Da)67,261
- Last updated2011-07-27 v3
- ChecksumA9B90E1EC78AEE37
Computationally mapped potential isoform sequences
There is 1 potential isoform mapped to this entry
Entry | Entry name | Gene name | Length | ||
---|---|---|---|---|---|
A0A0G2JF07 | A0A0G2JF07_MOUSE | Cfi | 145 |
Features
Showing features for sequence conflict.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Sequence conflict | 114 | in Ref. 1; AAB00438 | ||||
Sequence: K → N | ||||||
Sequence conflict | 236-252 | in Ref. 1; AAB00438 | ||||
Sequence: NGKHIPQEKACNGVNDC → MGSTFLRRKPATVSMTV | ||||||
Sequence conflict | 554 | in Ref. 1; AAB00438 | ||||
Sequence: I → T |
Keywords
- Technical term
Sequence databases
Nucleotide Sequence | Protein Sequence | Molecule Type | Status | |
---|---|---|---|---|
U47810 EMBL· GenBank· DDBJ | AAB00438.1 EMBL· GenBank· DDBJ | mRNA | ||
BC150751 EMBL· GenBank· DDBJ | AAI50752.1 EMBL· GenBank· DDBJ | mRNA | ||
AH007741 EMBL· GenBank· DDBJ | AAD32965.1 EMBL· GenBank· DDBJ | Genomic DNA |