RNA recognition motif (RRM)-like XS domain found in plants
This XS (named after rice gene X and SGS3) domain is a single-stranded RNA-binding domain (RBD) and possesses a unique version of a RNA recognition motif (RRM) fold. It is conserved in a family of plant proteins including gene X and SGS3. Although its function is still unknown, the plant SGS3 proteins are thought to be involved in post-transcriptional gene silencing (PTGS) pathways. In addition, they contain a conserved aspartate residue that may be functionally important.