Enables small GTPase binding activity. Involved in several processes, including defense response to Gram-positive bacterium; intracellular signal transduction; and vulval development. Expressed in head neurons and vulval precursor cell. Human ortholog(s) of this gene implicated in several diseases, including Noonan syndrome with multiple lentigines (multiple); carcinoma (multiple); and central nervous system benign neoplasm (multiple). Is an ortholog of human BRAF (B-Raf proto-oncogene, serine/threonine kinase).