Enables sialic acid binding activity. Predicted to be involved in complement activation, lectin pathway. Predicted to act upstream of or within innate immune response. Predicted to be extrinsic component of external side of plasma membrane. Predicted to be part of collagen trimer. Predicted to be active in collagen-containing extracellular matrix and extracellular space. Is expressed in bone marrow; embryo; liver; and spleen. Orthologous to several human genes including FCN1 (ficolin 1). [provided by Alliance of Genome Resources, Apr 2022]