The collagen-binding protein mediates bacterial adherence to collagen; the primary sequence has a non-repetitive, collagen-binding A region, followed by instances of this B region repetitive unit. The B region has one to four 23 kDa repeat units (B1-B4), which have been suggested to serve as 'stalks' that project the A region from the bacterial surface and thus facilitate bacterial adherence to collagen. Each B repeat unit has two highly similar domains (D1 and D2) placed side-by-side; both D1 and D2 are included in this model. They exhibit a unique inverse IgG-like domain fold.
Jiyao W et al.(2023). "The conserved domain database in 2023.",