STUDY ROUTES CATABÓLICAS RESPONSIBLE FOR THE ASSIMILATION OF 2-FENILETILAMINA AND 2-FENILETANOL IN PSEUDOMONAS PUTIDA U.Author:
ARIAS RIVAS SAGRARIO.
Year:
2006.
University:
LEÓN [
www.unileon.es].
Place of defense: FACULTAD DE VETERINARIA.
Place of preparation: FACULTAD DE VETERINARIA DE LA UNIVERSIDAD DE LEÓN.
Summary: The degradation 2-feniletilamina and 2-feniletanol in Pseudomonas putida U, and probably other species of the same gender, is carried out through two routes catabólicas different from those described in other microorganisms, which are part of a more complex catabolite called "catabolón of fenilacetil-CoA." This term refers to a functional unit consisting of different metabolic pathways that catalyze the transformation of Phenylacetic acid and related compounds structurally different with him until fenilacetil-CoA, as well as a central path that catalyzes the transformation of this tioéster in succinil- CoA. In P. Putida U degradation 2-feniletilamina and 2-feniletanol requires the participation of 37 genes organized into four different routes: two routes catabólicas (Pea route degradativa of 2-feniletilamina and Ped, route responsible for the assimilation of 2-feniletanol) and two routes anabólicas (Pqq, involved in the biosynthesis of cofactor PQQ and Ccm responsible for the biogenesis of cytochrome c), which together could be considered as a unit catabolite particular that catalyzes the oxidation of these compounds until Phenylacetic acid. We have identified and characterized 9 genes that are located in close proximity in a fragment of 16.6 kb and constituting the cluster pea responsible for the degradation 2-feniletilamina. Among the proteins encoded Pea in this gene cluster include: (i) a transport system (PeaHR), (ii) a quinohemoproteína amino dehydrogenase periplasmática (PeaABCD), (iii) an aldehyde dehydrogenase dependent NAD + (PeaE), and ( iv) two additional proteins (PeaFG), which until now had not been connected with the never catabolism of primary amines, which can form along with PeaE a complex enzyme involved in the oxidation of aldehyde generated by the QH-AmDH. We have identified and characterized 13 genes that make up the cluster ped (19.5 kb) and encoding enzymes necessary for the oxidation of 2-feniletanol to Phenylacetic acid. These proteins are: (i) a system of exclusion of alcohols ABC type (PedABC), (ii) two quinoproteínas alcohol deshidrogenasas periplasmáticas (PedE and PedH), (iii) a fenilacetaldehído dehydrogenase dependent NAD + (PedI), (iv) a soluble cytochrome c (PedF), (v) two proteins PedD and PedG, which had not been ever associated with the oxidation of alcohols and probably are involved in the entrance of 2-feniletanol inside cells, and (vi) two systems of two components sensor-regulador (PedS1R1 and PedS2R2). Although routes catabólicas Pea and Ped responsible for the assimilation of 2-feniletilamina and 2-feniletanol respectively, are not specific to the degradation of these compounds, but also recognize other primary amines (propilamina, butilamina and pentilamina) and other alcohols aliphatic (with a length of carbon chain between five and ten atoms) as substrates, we can consider them as two routes peripheral catabolón of fenilacetil-CoA because the degradation of both compounds leads to PhAc, to be degraded through the the central route of this catabolón. We have identified two other clusters (pqq and ccm) located in a fragment of DNA from 5.8 kb and 6.9 kb, respectively, which contain genes responsible for the biosynthesis of cofactor PQQ (PqqFABCDE) and the maturation of cytochrome c (CcmABCDGEFGHI). The mutation of one of these genes in P. Putida U resulted in the inability to absorb both 2-feniletilamina as 2-feniletanol (as well as other primary amines and alcohols) and, therefore, appear to be essential for the degradation of these compounds.
