title: Functional expression of an acyl carrier protein (ACP) from Azospirillum brasilense alters fatty acid profiles in Escherichia coli and Brassica juncea.
abstract: Acyl carrier protein (ACP) is a central cofactor for de novo fatty acid synthesis, acyl chain modification and chain-length termination during lipid biosynthesis in living organisms. Although the structural and functional organization of the ACPs in bacteria and plant are highly conserved, the individual ACP is engaged in the generation of sets of signature fatty acids required for specific purpose in bacterial cells and plant tissues. Realizing the fact that the bacterial ACP being originated early in molecular evolution is characteristically different from the plant's counterpart, we explored the property of an ACP from Azospirillum brasilense (Ab), a plant-associative aerobic bacterium, to find its role in changing the fatty acid profile in heterologous systems. Functional expression of Ab-ACP in Escherichia coli, an enteric bacterium, and Brassica juncea, an oil-seed crop plant, altered the fatty acid composition having predominantly 18-carbon acyl pool, reflecting the intrinsic nature of the ACP from A. brasilense which usually has C18:1 rich membrane lipid. In transgenic Brassica the prime increment was found for C18:3 in leaves; and C18:1 and C8:2 in seeds. Interestingly, the seed oil quality of the transgenic Brassica potentially improved for edible purposes, particularly with respect to the enhancement in the ratio of monounsaturated (C18:1)/saturated fatty acids, increment in the ratio of linoleic (C18:2)/linolenic (C18:3) and reduction of erucic acid (C22:1).
authors.affiliation: IIT-BREF Biotek, Indian Institute of Technology, Kharagpur 721302, India.
authors.forename: Jyoti K
authors.initials: JK
authors.lastname: Jha
authors.forename: Saheli
authors.initials: S
authors.lastname: Sinha
authors.forename: Mrinal K
authors.initials: MK
authors.lastname: Maiti
authors.forename: Asitava
authors.initials: A
authors.lastname: Basu
authors.forename: Ujjal K
authors.initials: UK
authors.lastname: Mukhopadhyay
authors.forename: Soumitra K
authors.initials: SK
authors.lastname: Sen
mesh_terms: D000213:Acyl Carrier Protein / Q000235:genetics* / Q000378:metabolism; D000595:Amino Acid Sequence; D015806:Azospirillum brasilense / Q000235:genetics*; D001426:Bacterial Proteins / Q000235:genetics; D029688:Brassica napus / Q000235:genetics* / Q000382:microbiology; D003001:Cloning, Molecular; D004926:Escherichia coli / Q000235:genetics*; D005227:Fatty Acids / Q000378:metabolism*; D007544:Isopropyl Thiogalactoside / Q000494:pharmacology; D007700:Kinetics; D008969:Molecular Sequence Data; D030821:Plants, Genetically Modified / Q000378:metabolism; D011994:Recombinant Proteins / Q000378:metabolism
chemical_list: D000213:Acyl Carrier Protein; D001426:Bacterial Proteins; D005227:Fatty Acids; D011994:Recombinant Proteins; D007544:Isopropyl Thiogalactoside