Part:BBa_K5314001
PKS (Polyketide Synthase)
PKS (Polyketide Synthase) is a diverse family of enzymes encoded by the PKS gene, responsible for synthesizing a variety of bioactive compounds, including antibiotics, antifungals, and pigments. The structure of PKS typically features multiple functional domains, such as the starter domain, which initiates the polyketide chain, the elongation domain, which adds carbon units, and the acyl transfer domain, which facilitates the transfer of acyl groups. These domains work in concert to catalyze complex biochemical reactions.
One of the critical functions of PKS is its role in catalyzing the synthesis of 1,3,6,8-tetrahydroxynaphthalene (1,3,6,8-THN) from acetyl-CoA and malonyl-CoA, marking the first key step in melanin biosynthesis in Aureobasidium melanogenum [1]. Melanin serves important roles in protecting the organism from environmental stressors.
In our project, the knockout of the PKS gene led to a marked reduction in melanin production, which in turn significantly increased β-glucan yield. β-glucan is a valuable polysaccharide known for its immunomodulatory properties and potential health benefits, making this enhancement beneficial for applications in nutraceuticals and functional foods. Additionally, by reducing melanin production, we minimized the formation of unwanted by-products, thereby improving overall metabolic efficiency and product purity.
Beyond its role in melanin synthesis, PKS is also the key enzyme in the first step of liamocin oil synthesis, controlling the production of 3,5-dihydroxydecanoic acid in Aureobasidium spp. [2]. Liamocin oil has garnered interest for its potential applications in natural products and pharmaceuticals due to its bioactive properties. Furthermore, PKS influences the biosynthesis of various pigments and mycotoxins across different fungal species, highlighting its versatility and importance in fungal metabolism [3]. This could enable the strategic manipulation of metabolic pathways to optimize the biosynthesis of multiple products, enhancing both yield and diversity.
By Cre-Lox recombination, we replaced the polyketide synthase controlled by PKS gene in Aureobasidium melanogenum BZ-11 with an antibiotic resistance gene (NAT) with promoter and polyA tail, which would subsequently be removed in the presence of Cre enzyme.
Source
Organism: Aureobasidium melanogenum BZ-11
GenBank: WNV28174.1
Sequence and Features
- 10INCOMPATIBLE WITH RFC[10]Illegal PstI site found at 1975
Illegal PstI site found at 2107 - 12INCOMPATIBLE WITH RFC[12]Illegal PstI site found at 1975
Illegal PstI site found at 2107 - 21INCOMPATIBLE WITH RFC[21]Illegal BglII site found at 1814
Illegal XhoI site found at 649
Illegal XhoI site found at 1864
Illegal XhoI site found at 2971
Illegal XhoI site found at 3619 - 23INCOMPATIBLE WITH RFC[23]Illegal PstI site found at 1975
Illegal PstI site found at 2107 - 25INCOMPATIBLE WITH RFC[25]Illegal PstI site found at 1975
Illegal PstI site found at 2107 - 1000INCOMPATIBLE WITH RFC[1000]Illegal BsaI site found at 507
Illegal BsaI site found at 658
Illegal BsaI.rc site found at 2002
Illegal SapI site found at 3408
Illegal SapI site found at 3855
References:
[1] Jia, S.-L., Chi, Z., Chen, L., Liu, G.-L., Hu, Z., & Chi, Z.-M. (2021b). Molecular evolution and regulation of DHN melanin-related gene clusters are closely related to adaptation of different melanin-producing fungi. Genomics, 113(4), 1962–1975. https://doi.org/10.1016/j.ygeno.2021.04.034
[2] Zhang, M., Wang, Z., Chi, Z., Liu, G.-L., & Chi, Z.-M. (2022). Metabolic engineering of Aureobasidium melanogenum 9–1 for overproduction of liamocins by enhancing supply of acetyl-CoA and ATP. Microbiological Research, 265, 127172. https://doi.org/10.1016/j.micres.2022.127172
[3] Chen, Y., Feng, P., Shang, Y., Xu, Y.-J., & Wang, C. (2015). Biosynthesis of non-melanin pigment by a divergent polyketide synthase in Metarhizium robertsii. Fungal Genetics and Biology, 81, 142–149. https://doi.org/10.1016/j.fgb.2014.10.018
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