A constitutive aldolase for 4-hydroxy-2-ketoglutarate in soil bacteria

The enzyme 4-hydroxy-2-oxoglutarate aldolase is deficient in primary hyperoxaluria type 3

“…Deficiency of HOGA could then cause the marked hyperoxaluria observed in PH3 by an accumulation of glyoxylate and metabolism of this substance to oxalate. The alternative is that accumulated 4-hydroxy-2-oxoglutarate, which is known to be relatively unstable [10], is metabolized either enzymatically or non-enzymatically to glyoxylate and/or oxalate. The direction of the HOGA enzyme reaction has significance for the treatment of PH3 since, if it is a forward (cleavage) reaction, reduction of dietary collagen could potentially reduce the amount of substrate and hence the amount of oxalate produced.…”

2-Keto-4-hydroxybutyrate aldolase. Identification as 2-keto-4-hydroxyglutarate aldolase, catalytic properties, and role in the mammalian metabolism of L-homoserine

“…Although earlier studies demonstrated that KHG-aldolase catalyzes a terminal step in the degradation of hydroxyproline by mammals, this same enzyme must now be regarded as also playing an important, previously unrecognized role in the metabolism of L-homoserine. A fairly general role of KHG-aldolase in metabolism is suggested by its presence in bacteria (Aronson et al, 1967;Nishihara and Dekker, 1969), in plants (Payes and Laties, 1963), and in several mammalian tissues (Maitra and Dekker, 1964).…”