Catalysis of the reaction: 3,4-dihydroxypyridine + O-acetyl-L-serine = 3-(3,4-dihydroxypyridinium-1-yl)-L-alanine + acetate.
O(3)-acetyl-L-serine acetate-lyase (adding 3,4-dihydroxypyridin-1-yl) activity