HLA-B Associated Transcript 2 (BAT2)

From cDNA clones, Banerji et al. (1990) determined the complete sequences of the closely linked BAT2 and BAT3 genes. The putative proteins are 228 and 110 kD, respectively, and do not appear to be members of any known family of proteins, although BAT3 contains an amino-terminal ubiquitin-like domain.

Both BAT2 and BAT3 are very rich in proline and include short tracts of polyproline, polyglycine, and charged amino acids. Thus they are similar to other proteins with large proline-rich domains, such as some nuclear proteins, collagens, elastin, and synapsin.UAP56 (BAT1) is an essential splicing factor that is recruited to the pre-mRNA dependent on U2AF65 and is required for the U2 snRNP-branchpoint interaction.