Catalyzes the dehydration of L-arabinonate to 2-dehydro-3-deoxy-L-arabinonate during L-arabinose degradation. Can also dehydrate D-galactonate and D-fuconate with good catalytic efficiency. Has weak activity with D-xylonate and D-gluconate. L-arabinonate = 2-dehydro-3-deoxy-L-arabinonate + H2O D-galactonate = 2-dehydro-3-deoxy-D-galactonate + H2O D-fuconate = 2-dehydro-3-deoxy-D-fuconate + H2O kcat is 728 min(-1) with L-arabinonate as substrate. kcat is 1377 min(-1) with D-galactonate as substrate. kcat is 2949 min(-1) with D-fuconate as substrate. kcat is 349 min(-1) with D-xylonate as substrate. kcat is 431 min(-1) with D-gluconate as substrate. Optimum pH is 8.0. Carbohydrate metabolism. Homotetramer. Belongs to the IlvD/Edd family.