CD55

Chr 1q32.2

CD55 molecule (Cromer blood group)

Aliases:: CR, TC, CROM
MANE:: ENST00000367064.9

OMIM: 125240 ↗NCBI: 1604 ↗Ensembl ↗

Annotations refreshed 1 month ago.

Predicted protein structure

AlphaFold predicted structure

CD55 · P08174

v62025-08-01

Predicted Aligned Error matrix for CD55 — diagonal shows residue index, colour shows pairwise prediction confidence (lower is better) — Predicted Aligned Error

Mean pLDDT

78.3/ 100

Confident

381 residues

Confidence breakdown

Very high(≥ 90)65%
Confident(70–90)1%
Low(50–70)5%
Very low(< 50)29%

Open interactive 3D viewer

AlphaFold (Jumper et al., 2021) · CC BY 4.0

Clinical relevance (Genomics England PanelApp)

Diagnostic Grade (Green)

COVID-19 research
BIALLELIC, autosomal or pseudoautosomal
Intestinal failure or congenital diarrhoea
BIALLELIC, autosomal or pseudoautosomal
Primary immunodeficiency or monogenic inflammatory bowel disease
BIALLELIC, autosomal or pseudoautosomal

Disease associations (Open Targets)

Protein-losing enteropathy
0.47
primary intestinal lymphangiectasia
0.47
complement deficiency
0.46
refractive error
0.37
myopia
0.37
Hypermetropia
0.33
diverticular disease
0.32
macular degeneration
0.32
cervical carcinoma
0.27
Venous thrombosis
0.26

Score is the Open Targets composite evidence score (0-1). Higher = stronger gene-disease association.

Protein function (UniProt)

Complement decay-accelerating factor

This protein recognizes C4b and C3b fragments that condense with cell-surface hydroxyl or amino groups when nascent C4b and C3b are locally generated during C4 and c3 activation. Interaction of daf with cell-associated C4b and C3b polypeptides interferes with their ability to catalyze the conversion of C2 and factor B to enzymatically active C2a and Bb and thereby prevents the formation of C4b2a and C3bBb, the amplification convertases of the complement cascade (PubMed:7525274). Inhibits complement activation by destabilizing and preventing the formation of C3 and C5 convertases, which prevents complement damage (PubMed:28657829)