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Functional analyses of three acyl-CoA synthetases involved in bile acid degradation in Pseudomonas putida DOC21.
Barrientos, Álvaro; Merino, Estefanía; Casabon, Israël; Rodríguez, Joaquín; Crowe, Adam M; Holert, Johannes; Philipp, Bodo; Eltis, Lindsay D; Olivera, Elías R; Luengo, José M.
Afiliação
  • Barrientos Á; Departmento de Biología Molecular, Facultad de Veterinaria, Universidad de León, León, Spain.
Environ Microbiol ; 17(1): 47-63, 2015 Jan.
Article em En | MEDLINE | ID: mdl-24428272
Pseudomonas putida DOC21, a soil-dwelling proteobacterium, catabolizes a variety of steroids and bile acids. Transposon mutagenesis and bioinformatics analyses identified four clusters of steroid degradation (std) genes encoding a single catabolic pathway. The latter includes three predicted acyl-CoA synthetases encoded by stdA1, stdA2 and stdA3 respectively. The ΔstdA1 and ΔstdA2 deletion mutants were unable to assimilate cholate or other bile acids but grew well on testosterone or 4-androstene-3,17-dione (AD). In contrast, a ΔstdA3 mutant grew poorly in media containing either testosterone or AD. When cells were grown with succinate in the presence of cholate, ΔstdA1 accumulated Δ(1/4) -3-ketocholate and Δ(1,4) -3-ketocholate, whereas ΔstdA2 only accumulated 7α,12α-dihydroxy-3-oxopregna-1,4-diene-20-carboxylate (DHOPDC). When incubated with testosterone or bile acids, ΔstdA3 accumulated 3aα-H-4α(3'propanoate)-7aß-methylhexahydro-1,5-indanedione (HIP) or the corresponding hydroxylated derivative. Biochemical analyses revealed that StdA1 converted cholate, 3-ketocholate, Δ(1/4) -3-ketocholate, and Δ(1,4) -3-ketocholate to their CoA thioesters, while StdA2 transformed DHOPDC to DHOPDC-CoA. In contrast, purified StdA3 catalysed the CoA thioesterification of HIP and its hydroxylated derivatives. Overall, StdA1, StdA2 and StdA3 are acyl-CoA synthetases required for the complete degradation of bile acids: StdA1 and StdA2 are involved in degrading the C-17 acyl chain, whereas StdA3 initiates degradation of the last two steroid rings. The study highlights differences in steroid catabolism between Proteobacteria and Actinobacteria.
Assuntos

Texto completo: 1 Coleções: 01-internacional Base de dados: MEDLINE Assunto principal: Ácidos e Sais Biliares / Pseudomonas putida / Coenzima A Ligases Idioma: En Revista: Environ Microbiol Assunto da revista: MICROBIOLOGIA / SAUDE AMBIENTAL Ano de publicação: 2015 Tipo de documento: Article País de afiliação: Espanha País de publicação: Reino Unido

Texto completo: 1 Coleções: 01-internacional Base de dados: MEDLINE Assunto principal: Ácidos e Sais Biliares / Pseudomonas putida / Coenzima A Ligases Idioma: En Revista: Environ Microbiol Assunto da revista: MICROBIOLOGIA / SAUDE AMBIENTAL Ano de publicação: 2015 Tipo de documento: Article País de afiliação: Espanha País de publicação: Reino Unido