Catalyzes the decomposition of L-selenocysteine to L-alanine and elemental selenium. AH2 + L-selenocysteine = A + H(+) + hydrogenselenide + L-alanine Homodimer. Up-regulated in acute glomerulonephritis. Regulated by JUN/AP-1. Belongs to the class-V pyridoxal-phosphate-dependent aminotransferase family. Truncated N-terminus.