Enables several functions, including protein homodimerization activity; ubiquitin protein ligase activity; and zinc ion binding activity. Involved in immune system development; positive regulation of T cell differentiation; and protein ubiquitination. Acts upstream of or within several processes, including T cell homeostasis; hematopoietic or lymphoid organ development; and negative regulation of apoptotic process. Located in nucleus. Is expressed in several structures, including arterial system; early conceptus; genitourinary system; gut; and hemolymphoid system. Human ortholog(s) of this gene implicated in Omenn syndrome; combined cellular and humoral immune defects with granulomas; severe combined immunodeficiency; and severe combined immunodeficiency, autosomal recessive, T cell-negative, B cell-negative, Nk cell-positive. Orthologous to human RAG1 (recombination activating 1). [provided by Alliance of Genome Resources, Apr 2022]