Arias, SagrarioSandoval, ÁngelArcos, MarcosMaestro García-Donas, María BeatrizSanz, JesúsNaharro, GermánLuengo, José2024-01-252024-01-252007Arias, Sagrario, et al. «Poly‐3‐hydroxyalkanoate Synthases from Pseudomonas Putida U: Substrate Specificity and Ultrastructural Studies». Microbial Biotechnology, vol. 1, n.o 2, marzo de 2008, pp. 170-76. https://doi.org/10.1111/j.1751-7915.2007.00016.x.10.1111/j.1751-7915.2007.00016.xhttps://hdl.handle.net/20.500.14352/95484Acknowledgments This work was supported by Grants from the Comisión Interministerial de Ciencia y Tecnología (CICYT), Madrid, España (Grants BIO2003-05309-C04-01, BIO2003-05309-C04-04 and BFU2006-15214-C03-03/BMC), Excma. Diputación Provincial de León (2005) and Junta de Castilla y León (LE40A06, 2006). S.A. and M.A. are recipients of fellowships from the Comisión Interministerial de Ciencia y Tecnología. All experiments reported in this paper comply with current Spanish legislation.The substrate specificity of the two polymerases (PhaC1 and PhaC2) involved in the biosynthesis of medium-chain-length poly-hydroxyalkanoates (mcl PHAs) in Pseudomonas putida U has been studied in vivo. For these kind of experiments, two recombinant strains derived from a genetically engineered mutant in which the whole pha locus had been deleted (P. putida U Δpha) were employed. These bacteria, which expresses only phaC1 (P. putida U Δpha pMC-phaC1) or only phaC2 (P. putida U Δpha pMC-phaC2), accumulated different PHAs in function of the precursor supplemented to the culture broth. Thus, the P. putida U Δpha pMC-phaC1 strain was able to synthesize several aliphatic and aromatic PHAs when hexanoic, heptanoic, octanoic decanoic, 5-phenylvaleric, 6-phenylhexanoic, 7-phenylheptanoic, 8-phenyloctanoic or 9-phenylnonanoic acid were used as precursors; the highest accumulation of polymers was observed when the precursor used were decanoic acid (aliphatic PHAs) or 6-phenylhexanoic acid (aromatic PHAs). However, although it synthesizes similar aliphatic PHAs (the highest accumulation was observed when hexanoic acid was the precursor) the other recombinant strain (P. putida U Δpha pMC-phaC2) only accumulated aromatic PHAs when the monomer to be polymerized was 3-hydroxy-5-phenylvaleryl-CoA. The possible influence of the putative three-dimensional structures on the different catalytic behaviour of PhaC1 and PhaC2 is discussed.engAttribution 4.0 Internationalhttp://creativecommons.org/licenses/by/4.0/journal article1751-7915https://doi.org/10.1111/j.1751-7915.2007.00016.xopen access577.1Bioquímica (Química)2403 Bioquímica