Abstract
In this chapter, new insights into substrate specificity during the elongation step of KS-catalysed polyketide biosynthesis are reported. Using a range of KS domains from the psymberin (Psy) and bacillaene (Bae) PKSs, each with different predicted acyl intermediates, together with MS-based methodology, the substrate tolerance at the elongation step is shown to be more demanding than the preceding acylation. A mechanism, based on reversible KS acylation, is proposed to rationalise this phenomenon, and is supported by experimental evidence. The rationally-designed mutant of BaeL KS5 described in Chap. 3, which is able to accept a β-Me branched acyl unit, is also shown to elongate this bulky acyl group in addition to 5- and 6-membered rings, demonstrating scope for engineering new polyketides.
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References
D.C. Gay et al., A close look at a ketosynthase from a trans-acyltransferase modular polyketide synthase. Structure 22, 444–451 (2014)
B. Busch et al., Multifactorial control of iteration events in a modular polyketide assembly line. Angew. Chem. Int. Ed. 52, 5285–5289 (2013)
M. Till, P.R. Race, Progress challenges and opportunities for the re-engineering of trans-AT polyketide synthases. Biotechnol. Lett. 36, 877–888 (2014)
R.J. Heath, C.O. Rock, The Claisen condensation in biology. Nat. Prod. Rep. 19, 581–596 (2002)
K. Watanabe, C.C.C. Wang, C.N. Boddy, D.E. Cane, C. Khosla, Understanding substrate specificity of polyketide synthase modules by generating hybrid multimodular synthases. J. Biol. Chem. 278, 42020–42026 (2003)
J.Q. Wu, K. Kinoshita, C. Khosla, D.E. Cane, Biochemical analysis of the substrate specificity of the beta-ketoacyl-acyl carrier protein synthase domain of module 2 of the erythromycin polyketide synthase. Biochemistry 43, 16301–16310 (2004)
L. Gu et al., GNAT-like strategy for polyketide chain initiation. Science 318, 970–974 (2007)
T. Nguyen et al., Exploiting the mosaic structure of trans-acyltransferase polyketide synthases for natural product discovery and pathway dissection. Nat. Biotechnol. 26, 225–233 (2008)
K.M. Fisch et al., Polyketide assembly lines of uncultivated sponge symbionts from structure-based gene targeting. Nat. Chem. Biol. 5, 494–501 (2009)
T. Gulder, M. Freeman, J. Piel, The catalytic diversity of multimodular polyketide synthases: natural product biosynthesis beyond textbook assembly rules. Top. Curr. Chem. 1–53 (2011)
D.C. Gay et al., A close look at a ketosynthase from a trans-acyltransferase modular polyketide synthase. Structure 22, 444–451 (2014)
C. Sanchez, L.C. Du, D.J. Edwards, M.D. Toney, B. Shen, Cloning and characterisation of a phosphopantetheinyl transferase from Streptomyces verticillus ATCC15003, the producer of the hybrid peptide-polyketide antitumor drug bleomycin. Chem. Biol. 8, 725–738 (2001)
K. Jensen et al., Polyketide proofreading by an acyltransferase-like enzyme. Chem. Biol. 19, 329–339 (2012)
A.T. Keatinge-Clay, The structures of type I polyketide synthases. Nat. Prod. Rep. 29, 1050–1073 (2012)
Y.-M. Zhang, J. Hurlbert, S.W. White, C.O. Rock, Roles of the active site water, histidine 303, and phenylalanine 396 in the catalytic mechanism of the elongation condensing enzyme of Streptococcus pneumoniae. J. Biol. Chem. 281, 17390–17399 (2006)
T. Hochmuth, J. Piel, Polyketide synthases of bacterial symbionts in sponges- Evolution-based applications in natural products research. Phytochemistry 70, 1841–1849 (2009)
P.J. Bracher, P.W. Snyder, B.R. Bohall, G.M. Whitesides, The relative rates of thiol-thioester exchange and hydrolysis for alkyl and aryl thioalkanoates in water. Origins Life Evol. B 41, 399–412 (2011)
A. Witkowski, A.K. Joshi, Y. Lindqvist, S. Smith, Conversion of a beta-ketoacyl synthase to a malonyl decarboxylase by replacement of the active-site cysteine with glutamine. Biochemistry 38, 11643–11650 (1999)
A. Witkowski, A.K. Joshi, S. Smith, Mechanism of the beta-ketoacyl synthase reaction catalyzed by the animal fatty acid synthase. Biochemistry 41, 10877–10887 (2002)
M.D. Lane, J. Moss, S.E. Polakis, Acetyl coenzyme A carboxylase. Curr. Top. Cell. Reg. 8, 139–195 (1974)
J. Moldenhauer, X.H. Chen, R. Borriss, J. Piel, Biosynthesis of the antibiotic bacillaene, the product of a giant polyketide synthase complex of the trans-AT family. Angew. Chem. Int. Ed. 46, 8195–8197 (2007)
S. Dutta et al., Structure of a modular polyketide synthase. Nature 510, 512–517 (2014)
J.R. Whicher et al., Structural rearrangements of a polyketide synthase module during its catalytic cycle. Nature 510, 560–564 (2014)
P.F. Leadlay, Structural biology: Enzyme assembly line pictured. Nature 510, 482–483 (2014)
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Jenner, M. (2016). Substrate Specificity of Ketosynthase Domains Part III: Elongation-Based Substrate Specificity. In: Using Mass Spectrometry for Biochemical Studies on Enzymatic Domains from Polyketide Synthases. Springer Theses. Springer, Cham. https://doi.org/10.1007/978-3-319-32723-5_6
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DOI: https://doi.org/10.1007/978-3-319-32723-5_6
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