| Primary Identifier | IPR003543 | Type | Family |
| Short Name | SR-AI/II |
| description | Scavenger receptors type I and II were the first scavenger receptors purified and are products of alternative splicing of a single gene. They are now named as class A, type I and type II (SR-AI/II) or collectively SR-A member 1. They can recognise a wide variety of ligands, from bacteria and yeast to self (native proteins) and self-modified ligands and they are involved in host defense, homeostasis, antigen presentation, pathogenesis of neurodegenerative disorders and atherosclerosis [, ]. The type I and type II human scavenger receptors are similar to their bovine, rabbit and murine counterparts. They consist of 6 domains: cytoplasmic (I); membrane-spanning (II); spacer (III); α-helical coiled-coil (IV); collagen-like (V); and a type-specific C-terminal (VI) []. Immunohistochemical studies have indicated the presence of scavenger receptors in the macrophages of lipid-rich atherosclerotic lesions, suggesting the involvement of these receptors in atherogenesis [].The macrophage scavenger receptor is trimeric and has unusual ligand-binding properties []. The trimeric structure of the bovine type I scavenger receptor contains 3 extracellular C-terminal cysteine-rich domains connected to the transmembrane domain by a long fibrous stalk. The stalk structure, which consists of an α-helical coiled coil and a collagen-like triple helix, has not previously been observed in an integral membrane protein []. |
