The Munc13 protein contains MUN (IPR010439). Two Ca2+/phospholipid binding C2 domains and a phorbol ester-binding C1 domain make up the Munc13 protein. It may function in a manner similar to Munc13. SRCR (IPR001190) is a scavenger receptor (SRCR) domain that is high in cysteine and can help proteins interact with each other and bind to ligands. It is present in a variety of cell surface proteins and secretory proteins, including the type I scavenger receptor, spermat receptor, CD5/Ly-1, CD6, and complement factor I. Scavenger receptors are a collection of diverse molecules that are located on the surface of phagocytes, primarily in macrophages and monocytes. For example, acetylated low-density lipoprotein is one type of ligand that scavenger receptors can recognize. They can also bind to a wide range of ligands.