L-arabinose degradation via L-arabinono-1,4-lactone pathway PMID:16326697 Degradation of L-arabinose via L-arabinono-1,4-lactone pathway. In this catabolic pathway, L-arabinose is oxidized to L-arabino-gamma-lactone (L-arabinono-1,4-lactone) by a NAD(P)+-dependent dehydrogenase. The lactone is cleaved by a lactonase to L-arabonate, followed by two successive dehydration reactions forming L-2-keto-3-deoxyarabonate (L-KDA)2 and alpha-ketoglutaric semialdehyde(alpha-KGSA). The last step is the NAD(P)+-dependent dehydrogenation of alpha-KGSA to alpha-ketoglutaric acid (referred to as the first pathway). Alternatively, L-KDA is cleaved through an aldolase reaction to glycolaldehyde and pyruvate (referred to as the second pathway). GO:0019570 KEGG:map00053 PMID:16950779 UPa:UPA00141 MetaCyc:PWY-5517 KEGG:map00040 pathway PMID:17202142 KEGG:map01100 carbohydrate degradation L-arabinose degradation