Enables several functions, including MHC class I protein binding activity; MHC class Ib receptor activity; and identical protein binding activity. Involved in positive regulation of natural killer cell mediated cytotoxicity. Acts upstream of or within several processes, including positive regulation of interferon-gamma production; positive regulation of nitric oxide biosynthetic process; and response to bacterium. Located in external side of plasma membrane. Human ortholog(s) of this gene implicated in tropical spastic paraparesis. Orthologous to several human genes including KLRC4-KLRK1 (KLRC4-KLRK1 readthrough). [provided by Alliance of Genome Resources, Apr 2022]