CLEC4A3 contains 1 C-type lectin domain and belongs to the C-type lectin-like domain-containing (CLEC) family. Lectins are proteins that are able to recognize and bind with specific carbohydrate molecules. C-type lectins are an important group of proteins found in the immune system of animals. These lectins are named C-type because of their calcium dependent carbohydrate recognition domain (CRD). In the immune system, C-type lectins act as recognition molecules by binding to foreign microorganisms. They also promote the movement and selective adhesion of white blood cells. The C-type lectin has a three-dimensional fold, the CRD, in which calcium ions contribute to the lectin's ability to recognize and bind carbohydrates. In the immune system, carbohydrate recognition contributes to the ability of immune cells to move from one area of the body to another. It also allows immune cells to identify and discriminate between proteins that belong to the host and those that belong to foreign organisms. There are a number of different C-type lectin subfamilies, including collectins, selectins, proteoglycans, and lymphocyte lectins.

> 95 % as determined by SDS-PAGE.