Enzymes and pathways of polyamine breakdown in microorganisms

Abstract

The information currently available on the breakdown of spermidine and putrescine by microorganisms is reviewed. Two major metabolic routes have been described, one for the free bases via δ1‐pyrroline (4‐aminobutyraldehyde), the other via N‐acetyl derivatives. In both pathways oxidases or aminotransferases are the key enzymes in removing the nitrogen atoms. The two routes converge at 4‐aminobutyrate, which is then metabolized via succinate. The degradation of putrescine in Escherichia coli has been well characterized at both genetic and biochemical levels, but for other bacteria much less information is available. The C3 moiety of spermidine is broken down via β‐alanine, but the metabolism of this compound and its precursors is poorly understood. In yeasts, a catabolic route for spermidine and putrescine via N‐acetyl derivatives has been described in Candida boidinii, and the evidence for its occurrence in other species is reviewed. Except for the terminal step of this pathway, the same group of enzymes can metabolize both the C3 and C4 moieties of spermidine. It is likely that other routes of polyamine catabolism also exist in both bacteria and yeasts.

Discovery and characterization of a putrescine oxidase from Rhodococcus erythropolis NCIMB 11540

“…The physiological role of putrescine oxidase in R. erythropolis is probably related to polyamine degradation (Large 1992 ), which is supported by the presence of a neighboring gene encoding a putative aldehyde dehydrogenase on the sequenced DNA fragment (data not shown). PuO Rh displays 67% sequence identity with PuO Mr , which is the only bacterial putrescine oxidase that has been characterized so far.…”

The inducers 1,3-diaminopropane and spermidine cause the reprogramming of metabolism in Penicillium chrysogenum, leading to multiple vesicles and penicillin overproduction

“…In yeast, the formation of pantoate involves the same enzymatic steps as in bacteria, whereas β-alanine biosynthesis differs from that and is dependent upon polyamine biosynthesis and upon the amine oxidase encoded by the fms1 gene [71]. Amine oxidases can degrade polyamines with the production of the aldehyde compound 3-aminopropanal [72,73], implying that further oxidation of 3-aminopropanal by an aldehyde dehydrogenase would also be required for β-alanine biosynthesis in yeast [30]. This result correlates well with the increase in the spermidine synthase (giving rise to high levels of spermidine) and with the increase in the biosynthesis of acetyl-CoA by ATP citrate lyase ACL1 and dihydrolipoamide dehydrogenase Lpd1, since β-alanine is an intermediate required for the biosynthesis of coenzyme A.…”

A subfamily of PLP-dependent enzymes specialized in handling terminal amines

“…(1) to the right. In vivo, the reactions catalyzed by these enzymes are strongly biased in favor of degradation of the ω-amino substrate [30,31].…”