title: Comparison of medium-chain-length polyhydroxyalkanoates synthases from Pseudomonas mendocina NK-01 with the same substrate specificity.
abstract: The medium-chain-length polyhydroxyalkanoate (PHAMCL) synthase genes phaC1 and phaC2 of Pseudomonas mendocina NK-01 were cloned and inserted into expression plasmid pBBR1MCS-2 to form pBBR1MCS-C1 and pBBR1MCS-C2 which were expressed respectively in the PHAMCL-negative strain P. mendocina C7 whose PHAMCL synthesis operon was defined knock out. P. mendocina C7 derivatives P. mendocina C7C1 and C7C2 carrying pBBR1MCS-C1 and pBBR1MCS-C2 respectively were constructed. Fermentation and gel permeation chromatography (GPC) revealed that P. mendocina C7C1 had higher PHAMCL production rate but its PHAMCL had lower molecular weight than that of P. mendocina C7C2. Gas chromatograph/mass spectrometry (GC/MS) analysis revealed that the two PHAMCL had similarity in monomer composition with 3HD as the favorite monomer i.e. PhaC1 and PhaC2 had the same substrate specificity. Differential scanning calorimetry (DSC), thermogravimetric analysis (TGA) and X-ray diffraction (XRD) also revealed that the two PHAMCL had the same physical properties. P. mendocina NK-01was the first reported strain whose PHAMCL synthases PhaC1 and PhaC2 had the same substrate specificity.
authors.affiliation: Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Department of Microbiology, College of Life Sciences, Nankai University, Tianjin 300071, China.
authors.forename: Wenbin
authors.initials: W
authors.lastname: Guo
authors.forename: Jingjing
authors.initials: J
authors.lastname: Duan
authors.forename: Weitao
authors.initials: W
authors.lastname: Geng
authors.forename: Jun
authors.initials: J
authors.lastname: Feng
authors.forename: Shufang
authors.initials: S
authors.lastname: Wang
authors.forename: Cunjiang
authors.initials: C
authors.lastname: Song
mesh_terms: D000217:Acyltransferases / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D008969:Molecular Sequence Data; D054813:Polyhydroxyalkanoates / Q000378:metabolism; D044203:Pseudomonas mendocina / Q000737:chemistry / Q000201:enzymology* / Q000235:genetics; D016415:Sequence Alignment; D013379:Substrate Specificity
chemical_list: D001426:Bacterial Proteins; D054813:Polyhydroxyalkanoates; D000217:Acyltransferases; C077225:poly(3-hydroxyalkanoic acid) synthase