title: Threonine aldolases: perspectives in engineering and screening the enzymes with enhanced substrate and stereo specificities.
abstract: Threonine aldolases have emerged as a powerful tool for asymmetric carbon-carbon bond formation. These enzymes catalyse the unnatural aldol condensation of different aldehydes and glycine to produce highly valuable β-hydroxy-α-amino acids with complete stereocontrol at the α-carbon and moderate specificity at the β-carbon. A range of microbial threonine aldolases has been recently recombinantly produced by several groups and their biochemical properties were characterized. Numerous studies have been conducted to improve the reaction protocols to enable higher conversions and investigate the substrate scope of enzymes. However, the application of threonine aldolases in organic synthesis is still limited due to often moderate yields and low diastereoselectivities obtained in the aldol reaction. This review briefly summarizes the screening techniques recently applied to discover novel threonine aldolases as well as enzyme engineering and mutagenesis studies which were accomplished to improve the catalytic activity and substrate specificity. Additionally, the results from new investigations on threonine aldolases including crystal structure determinations and structural-functional characterization are reviewed.
authors.affiliation: Institute of Organic Chemistry, Graz University of Technology, Stremayrgasse 9, A-8010, Graz, Austria. kateryna.lypetska@tugraz.at.
authors.forename: Kateryna
authors.initials: K
authors.lastname: Fesko
mesh_terms: D000447:Aldehydes / Q000378:metabolism; D005998:Glycine / Q000378:metabolism; D012696:Glycine Hydroxymethyltransferase / Q000235:genetics* / Q000378:metabolism*; D008403:Mass Screening; D015202:Protein Engineering; D013379:Substrate Specificity
chemical_list: D000447:Aldehydes; D012696:Glycine Hydroxymethyltransferase; D005998:Glycine
keywords: Aldol reactions; Biocatalysis; Enzyme engineering; Screening; Threonine aldolase
references.citation: J Microbiol Biotechnol. 2007 May;17(5):721-7
references.pmid: 18051291
references.citation: Acta Crystallogr D Biol Crystallogr. 2014 Jun;70(Pt 6):1695-703
references.pmid: 24914980
references.citation: Biochemistry. 2002 Oct 1;41(39):11711-20
references.pmid: 12269813
references.citation: Biotechnol Lett. 2010 Jan;32(1):143-9
references.pmid: 19760118
references.citation: Enzyme Microb Technol. 2014 Jun 10;60:47-55
references.pmid: 24835099
references.citation: Comput Struct Biotechnol J. 2012 Nov 13;2:e201209016
references.pmid: 24688657
references.citation: Angew Chem Int Ed Engl. 2010;49(1):121-4
references.pmid: 19943295
references.citation: Enzyme Microb Technol. 2014 Dec;67:1-7
references.pmid: 25442942
references.citation: Nat Biotechnol. 2007 Oct;25(10):1145-7
references.pmid: 17873865
references.citation: Curr Opin Chem Biol. 2013 Apr;17(2):215-20
references.pmid: 23523243
references.citation: FEBS J. 2014 Jan;281(1):129-45
references.pmid: 24165453
references.citation: Appl Microbiol Biotechnol. 2007 Nov;77(1):241-4
references.pmid: 17786428
references.citation: J Biol Chem. 1998 Jul 3;273(27):16678-85
references.pmid: 9642221
references.citation: J Mol Evol. 2015 Feb;80(2):102-7
references.pmid: 25644973
references.citation: Appl Microbiol Biotechnol. 2005 Sep;68(4):489-97
references.pmid: 15726349
references.citation: Amino Acids. 2011 Jan;40(1):215-20
references.pmid: 20514546
references.citation: Appl Microbiol Biotechnol. 2010 Sep;88(2):409-24
references.pmid: 20683718
references.citation: J Biotechnol. 2015 Apr 10;199:69-76
references.pmid: 25701680
references.citation: Adv Appl Microbiol. 2014;88:57-101
references.pmid: 24767426
references.citation: Chemistry. 2008;14(15):4647-56
references.pmid: 18384024
references.citation: Prep Biochem Biotechnol. 2012;42(2):143-54
references.pmid: 22394063
references.citation: Angew Chem Int Ed Engl. 2015 Mar 2;54(10):3013-7
references.pmid: 25611820
references.citation: PLoS One. 2015;10(4):e0124056
references.pmid: 25884707
references.citation: Biochim Biophys Acta. 2015 Apr;1854(4):278-83
references.pmid: 25560296
references.citation: Appl Microbiol Biotechnol. 2015 Jul;99(14):5875-83
references.pmid: 25616526
references.citation: Appl Microbiol Biotechnol. 2015 Nov;99(22):9651-61
references.pmid: 26189018
references.citation: Mol Syst Biol. 2010 Nov 30;6:436
references.pmid: 21119630
references.citation: Beilstein J Org Chem. 2013 Oct 22;9:2168-79
references.pmid: 24204429