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Identification of Thermotoga Maritima MSB8 GH57 α-amylase AmyC As a Glycogen-branching Enzyme with High Hydrolytic Activity

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Date 2019 Jun 14
PMID 31190240
Citations 4
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Abstract

AmyC, a glycoside hydrolase family 57 (GH57) enzyme of Thermotoga maritima MSB8, has previously been identified as an intracellular α-amylase playing a role in either maltodextrin utilization or storage polysaccharide metabolism. However, the α-amylase specificity of AmyC is questionable as extensive phylogenetic analysis of GH57 and tertiary structural comparison suggest that AmyC could actually be a glycogen-branching enzyme (GBE), a key enzyme in the biosynthesis of glycogen. This communication presents phylogenetic and biochemical evidence that AmyC is a GBE with a relatively high hydrolytic (α-amylase) activity (up to 30% of the total activity), creating a branched α-glucan with 8.5% α-1,6-glycosidic bonds. The high hydrolytic activity is explained by the fact that AmyC has a considerably shorter catalytic loop (residues 213-220) not reaching the acceptor side. Secondly, in AmyC, the tryptophan residue (W 246) near the active site has its side chain buried in the protein interior, while the side chain is at the surface in Tk1436 and Tt1467 GBEs. The putative GBEs from three other Thermotogaceae, with very high sequence similarities to AmyC, were found to have the same structural elements as AmyC, suggesting that GH57 GBEs with relatively high hydrolytic activity may be widespread in nature.

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References
1.
Santos C, Tonoli C, Trindade D, Betzel C, Takata H, Kuriki T . Structural basis for branching-enzyme activity of glycoside hydrolase family 57: structure and stability studies of a novel branching enzyme from the hyperthermophilic archaeon Thermococcus kodakaraensis KOD1. Proteins. 2010; 79(2):547-57. DOI: 10.1002/prot.22902. View

2.
. Activities at the Universal Protein Resource (UniProt). Nucleic Acids Res. 2013; 42(Database issue):D191-8. PMC: 3965022. DOI: 10.1093/nar/gkt1140. View

3.
Imamura H, Fushinobu S, Yamamoto M, Kumasaka T, Jeon B, Wakagi T . Crystal structures of 4-alpha-glucanotransferase from Thermococcus litoralis and its complex with an inhibitor. J Biol Chem. 2003; 278(21):19378-86. DOI: 10.1074/jbc.M213134200. View

4.
McCleary B, McGeough P . A Comparison of Polysaccharide Substrates and Reducing Sugar Methods for the Measurement of endo-1,4-β-Xylanase. Appl Biochem Biotechnol. 2015; 177(5):1152-63. PMC: 4633439. DOI: 10.1007/s12010-015-1803-z. View

5.
Blesak K, Janecek S . Sequence fingerprints of enzyme specificities from the glycoside hydrolase family GH57. Extremophiles. 2012; 16(3):497-506. DOI: 10.1007/s00792-012-0449-9. View