Immunogen sequence: MSYMLPHLHNG WQVDQAILSE EDRVVVIRFG HDWDPTCMKM DEVLYSIAEK VKNFAVIYLV DITEVPDFNK Highest antigen sequence identity to the following orthologs - mouse 100%, rat 100%. Essential role in pre-mRNA splicing as component of the U5 snRNP and U4