UDP-glucose 4,6-dehydratase that converts UDP-glucose into UDP-4-keto-6-deoxyglucose, and which is required for glycosaminoglycan biosynthesis and skeletal development (PubMed:40836090). UDP-4-keto-6- deoxyglucose is a mimic of the reaction intermediate of UXS1 and acts as an enzyme-rescue metabolite to promote the completion of UXS1 catalytic cycle when NAD(+) levels are low (PubMed:40836090). Under low NAD(+) conditions, UXS1 forms an inactive UDP-4-ketoxylose intermediate bound to NADH, impairing the synthesis of specific glycans that are essential for skeletal development (PubMed:40836090). UDP-4-keto-6- deoxyglucose is used by the inactive NADH-bound UXS1 to produce UDP-6- deoxyglucose and NAD(+) within the catalytic pocket of UXS1, regenerating the essential cofactor NAD(+) (PubMed:40836090). . This is the function of TGDS (TDP-glucose 4,6-dehydratase, ENSG00000088451).