Involved in the degradation of L-fucose and D-arabinose (PubMed:13898172). Catalyzes the reversible cleavage of L-fuculose 1-phosphate (Fuc1P) to yield dihydroxyacetone phosphate (DHAP) and L-lactaldehyde (PubMed:13898172, Ref.8, Ref.9, PubMed:10821675, PubMed:11054289). Also able to catalyze the reversible cleavage of D-ribulose 1-phosphate, but FucA has a higher affinity for L-fuculose 1-phosphate and L-lactaldehyde than for D-ribulose 1-phosphate and glycolaldehyde, respectively (PubMed:4928018). FucA possesses a high specificity for the dihydroxyacetone phosphate (DHAP), but accepts a great variety of different aldehydes and has a strong preference for L-configurated alpha-hydroxy aldehydes (PubMed:13898172, Ref.8, PubMed:10821675). FucA generates a vicinal diol unit having the absolute (3R,4R)-cis configuration (D-erythro) (Ref.8, PubMed:10821675). L-fuculose 1-phosphate = (S)-lactaldehyde + dihydroxyacetone phosphate Binds 1 zinc ion per subunit. Inhibited by phosphoglycolohydroxamate (PGH). kcat is 19.3 sec(-1) for L-fuculose 1-phosphate (Fuc1P) as substrate. Optimum pH is 7.2. Carbohydrate degradation; L-fucose degradation; L-lactaldehyde and glycerone phosphate from L-fucose: step 3/3. Homotetramer. By L-fucose. During catalysis the binding of dihydroxyacetone phosphate (DHAP) frees Glu-73 residue from its interaction with zinc ion (PubMed:10821675, PubMed:11054289). Then Glu-73 residue abstracts a proton from the C3 atom of dihydroxyacetone phosphate (DHAP) (or from the O4 atom of L-fuculose 1-phosphate (Fuc1P) in the backward reaction), and moves to transfer its proton to the aldehyde oxygen atom (or to the C3 atom of dihydroxyacetone phosphate (DHAP)) (PubMed:10821675, PubMed:11054289). Belongs to the aldolase class II family. AraD/FucA subfamily.