This view shows enzymes only for those organisms listed below, in the list of taxa known to possess the pathway. If an enzyme name is shown in bold, there is experimental evidence for this enzymatic activity.
|Superclasses:||Degradation/Utilization/Assimilation → Amines and Polyamines Degradation → Urea Degradation|
Many organisms possess enzymes for the transformation of urea into ammonia and CO2. This conversion can occur in two distinct routes, catalyzed by the enzymes urease and urea carboxylase, respectively.
urease catalyzes the ATP independent cleavage of the amide bonds of urea, forming ammonia and CO2 in a single step. Ureases have been described in plants, fungi, and bacteria, and have been extensively characterized.
The enzyme is particularly important for the human pathogen Helicobacter pylori, which uses ammonia production by urease for raising the pH in its microenvironment, as well as for controlling the pH homeostasis within the cell [Benoit07]. In that organism, urease accounts for 10-15% of the total protein content of the cell [Bauerfeind97].
Superpathways: superpathway of allantoin degradation in plants
Variants: urea degradation I
Benoit07: Benoit SL, Mehta N, Weinberg MV, Maier C, Maier RJ (2007). "Interaction between the Helicobacter pylori accessory proteins HypA and UreE is needed for urease maturation." Microbiology 153(Pt 5);1474-82. PMID: 17464061
Chen96a: Chen YY, Clancy KA, Burne RA (1996). "Streptococcus salivarius urease: genetic and biochemical characterization and expression in a dental plaque streptococcus." Infect Immun 1996;64(2);585-92. PMID: 8550211
Lee92d: Lee MH, Mulrooney SB, Renner MJ, Markowicz Y, Hausinger RP (1992). "Klebsiella aerogenes urease gene cluster: sequence of ureD and demonstration that four accessory genes (ureD, ureE, ureF, and ureG) are involved in nickel metallocenter biosynthesis." J Bacteriol 174(13);4324-30. PMID: 1624427
Lee93a: Lee MH, Pankratz HS, Wang S, Scott RA, Finnegan MG, Johnson MK, Ippolito JA, Christianson DW, Hausinger RP (1993). "Purification and characterization of Klebsiella aerogenes UreE protein: a nickel-binding protein that functions in urease metallocenter assembly." Protein Sci 2(6);1042-52. PMID: 8318889
Miksch94: Miksch G, Arnold W, Lentzsch P, Priefer UB, Puhler A (1994). "A 4.6 kb DNA region of Rhizobium meliloti involved in determining urease and hydrogenase activities carries the structural genes for urease (ureA, ureB, ureC) interrupted by other open reading frames." Mol Gen Genet 242(5);539-50. PMID: 8121412
Park94: Park IS, Carr MB, Hausinger RP (1994). "In vitro activation of urease apoprotein and role of UreD as a chaperone required for nickel metallocenter assembly." Proc Natl Acad Sci U S A 91(8);3233-7. PMID: 7909161
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