If an enzyme name is shown in bold, there is experimental evidence for this enzymatic activity.
Locations of Mapped Genes:
|Superclasses:||Degradation/Utilization/Assimilation → Amines and Polyamines Degradation → Putrescine Degradation|
Polyamines (the most common of which are putrescine, spermidine, and spermine), a group of positively charged small molecules present in virtually all living organisms, have been implicated in many biological processes, including binding to nucleic acids, stabilizing membranes, and stimulating several enzymes [Tabor85, Abraham68, Frydman92, Huang90b]. Although polyamines are clearly necessary for optimal cell growth, a surplus of polyamines can cause inhibition of growth and protein synthesis [He93], and thus a balance is desired between the production and breakdown of polyamines.
Putrescine catabolism appears to be important for responding to a variety of stresses. An E. coli strain that lacks both putrescine degradation I and putrescine degradation II pathways has a severe growth defect under oxidative stress conditions, and shows impaired growth at high temperature or sublethal antibiotic concentrations [Schneider13].
About This Pathway
Several metabolic pathways for putrescine degradation as a source of nitrogen for E. coli K-12 are known. The first putrescine degradation pathway was found in in 1985 [Shaibe85a] (see putrescine degradation I). That pathway is dedicated to the degradation of intracellular putrescine. A second pathway was found in E. coli K-12 twenty years later. This pathway seems to be dedicated to the degradation of extracellular putrescine [Kurihara05].
The pathway was discovered following the discovery of a cluster of seven unassigned genes on the E. coli K-12 chromosome. In addition to a putrescine transporter, encoded by the puuP gene, the cluster contains four genes that encode the enzymes involved in this pathway, and two additional genes (puuE and puuR) that encode an enzyme involved in the catabolism of GABA (see superpathway of 4-aminobutanoate degradation) and a regulator [Kurihara05].
In this pathway, putrescine is γ-glutamylated at the expense of an ATP molecule. The resulting γ-glutamyl-putrescine is oxidized to γ-glutamyl-γ-aminobutyraldehyde, which is then dehydrogenated into 4-(glutamylamino) butanoate. In the last step, the γ-glutamyl group is removed by hydrolysis, generating 4-aminobutyrate.
Wild type E. coli cells are unable to utilize putrescine as the sole source of carbon at temperatures above 30°C [Schneider12]. It is possible to select for mutants that possess this ability; these mutants contain elevated levels of the enzymes in this pathway [PrietoSantos86].
Variants: putrescine degradation I
Abraham68: Abraham KA (1968). "Studies on DNA-dependent RNA polymerase from Escherichia coli. 1. The mechanism of polyamine induced stimulation of enzyme activity." Eur J Biochem 5(1);143-6. PMID: 4873311
Frydman92: Frydman L, Rossomando PC, Frydman V, Fernandez CO, Frydman B, Samejima K (1992). "Interactions between natural polyamines and tRNA: an 15N NMR analysis." Proc Natl Acad Sci U S A 89(19);9186-90. PMID: 1409623
He93: He Y, Kashiwagi K, Fukuchi J, Terao K, Shirahata A, Igarashi K (1993). "Correlation between the inhibition of cell growth by accumulated polyamines and the decrease of magnesium and ATP." Eur J Biochem 217(1);89-96. PMID: 8223591
Huang90b: Huang SC, Panagiotidis CA, Canellakis ES (1990). "Transcriptional effects of polyamines on ribosomal proteins and on polyamine-synthesizing enzymes in Escherichia coli." Proc Natl Acad Sci U S A 87(9);3464-8. PMID: 2185470
Kurihara05: Kurihara S, Oda S, Kato K, Kim HG, Koyanagi T, Kumagai H, Suzuki H (2005). "A novel putrescine utilization pathway involves gamma-glutamylated intermediates of Escherichia coli K-12." J Biol Chem 280(6);4602-8. PMID: 15590624
PrietoSantos86: Prieto-Santos MI, Martin-Checa J, Balana-Fouce R, Garrido-Pertierra A (1986). "A pathway for putrescine catabolism in Escherichia coli." Biochim Biophys Acta 1986;880(2-3);242-4. PMID: 3510672
Shaibe85a: Shaibe E, Metzer E, Halpern YS (1985). "Metabolic pathway for the utilization of L-arginine, L-ornithine, agmatine, and putrescine as nitrogen sources in Escherichia coli K-12." J Bacteriol 163(3);933-7. PMID: 3897201
DiazMejia09: Diaz-Mejia JJ, Babu M, Emili A (2009). "Computational and experimental approaches to chart the Escherichia coli cell-envelope-associated proteome and interactome." FEMS Microbiol Rev 33(1);66-97. PMID: 19054114
Jo08: Jo JE, Mohan Raj S, Rathnasingh C, Selvakumar E, Jung WC, Park S (2008). "Cloning, expression, and characterization of an aldehyde dehydrogenase from Escherichia coli K-12 that utilizes 3-Hydroxypropionaldehyde as a substrate." Appl Microbiol Biotechnol 81(1);51-60. PMID: 18668238
Kurihara06: Kurihara S, Oda S, Kumagai H, Suzuki H (2006). "gamma-Glutamyl-gamma-aminobutyrate hydrolase in the putrescine utilization pathway of Escherichia coli K-12." FEMS Microbiol Lett 256(2);318-23. PMID: 16499623
Kurihara08: Kurihara S, Oda S, Tsuboi Y, Kim HG, Oshida M, Kumagai H, Suzuki H (2008). "gamma -glutamylputrescine synthetase in the putrescine utilization pathway of Escherichia coli K-12." J Biol Chem. PMID: 18495664
Partridge06: Partridge JD, Scott C, Tang Y, Poole RK, Green J (2006). "Escherichia coli transcriptome dynamics during the transition from anaerobic to aerobic conditions." J Biol Chem 281(38);27806-15. PMID: 16857675
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