Enables several functions, including phosphatidylinositol phosphate binding activity; phosphatidylinositol-3,4-bisphosphate binding activity; and zinc ion binding activity. Involved in V(D)J recombination and pre-B cell allelic exclusion. Acts upstream of or within several processes, including B cell homeostatic proliferation; lymphocyte differentiation; and positive regulation of organ growth. Predicted to be located in nucleoplasm. Predicted to be part of DNA recombinase complex. Is expressed in gut; hemolymphoid system; and liver. Used to study Omenn syndrome and severe combined immunodeficiency, autosomal recessive, T cell-negative, B cell-negative, Nk cell-positive. 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 RAG2 (recombination activating 2). [provided by Alliance of Genome Resources, Apr 2022]