The scavenger receptor cysteine-rich (SRCR) domain is an ancient and highly conserved domain of about 110 residues which is found in diverse secreted and cell-surface proteins, like the type I scavenger receptor, the speract receptor, CD5/Ly-1, CD6, or complement factor I [ PUBMED:1978939 ]. Tandem repeats of SRCR domains … expand

The scavenger receptor cysteine-rich (SRCR) domain is an ancient and highly conserved domain of about 110 residues which is found in diverse secreted and cell-surface proteins, like the type I scavenger receptor, the speract receptor, CD5/Ly-1, CD6, or complement factor I [ PUBMED:1978939 ]. Tandem repeats of SRCR domains are common in the membrane bound proteins. Most SRCR domains have six to eight cysteines that participate in intradomain disulfide bonds. SRCR domains have been subdivided into two groups, A and B, primarily on the differences in the spacing pattern between the cysteine residues [ PUBMED:8140623 PUBMED:10074941 ].

Although the biochemical functions of SRCR domains have not been established with certainty, they are likely to mediate protein-protein interactions and ligand binding [ PUBMED:8140623 PUBMED:10074941 ].

Determination of the crystal structure of the SRCR domain of M2BP reveals that the M2NP SRCR adopts a compact fold of approximate dimensions 22 x 26 x 30 Angstrom, organised around a curved six-stranded β-sheet cradling an alpha- helix [ PUBMED:10074941 ].