Carbohydrate active enzyme domains from extreme thermophiles: components of a modular toolbox for lignocellulose degradation
Lignocellulosic biomass is a promising feedstock for the manufacture of biodegradable and renewable bioproducts. However, the complex lignocellulosic polymeric structure of woody tissue is difficult to access without extensive industrial pre-treatment. Enzyme processing of partly depolymerised biomass is an established technology, and there is evidence that high temperature (extremely thermophilic) lignocellulose degrading enzymes [carbohydrate active enzymes (CAZymes)] may enhance processing efficiency. However, wild-type thermophilic CAZymes will not necessarily be functionally optimal under industrial pre-treatment conditions. With recent advances in synthetic biology, it is now potentially possible to build CAZyme constructs from individual protein domains, tailored to the conditions of specific industrial processes. In this review, we identify a ‘toolbox’ of thermostable CAZyme domains from extremely thermophilic organisms and highlight recent advances in CAZyme engineering which will allow for the rational design of CAZymes tailored to specific aspects of lignocellulose digestion.
KeywordsLignocellulose CAZyme Extreme thermophiles Synthetic biology Protein domains
The authors wish to thank the National Research Foundation (South Africa) for financial support.
Compliance with ethical standards
Conflict of interest
The authors declare no conflict of interest.
- Czjzek M, Ficko-Blean E (2017) Probing the complex architecture of multimodular carbohydrate-active enzymes using a combination of small angle X-ray scattering and X-ray crystallography protein-carbohydrate interactions. Methods Protoc 1588:239–253Google Scholar
- Espina G, Eley K, Pompidor G, Schneider TR, Crennell SJ, Danson MJ (2014) A novel β-xylosidase structure from Geobacillus thermoglucosidasius: the first crystal structure of a glycoside hydrolase family GH52 enzyme reveals unpredicted similarity to other glycoside hydrolase folds. Acta Crystallogr D Biol Crystallogr 70:1366–1374PubMedCrossRefGoogle Scholar
- Fatima B, Hussain Z (2015) Xylose isomerases from thermotogales. J Anim Plant Sci 25(1):10–18Google Scholar
- Ferrara MC, Cobucci-Ponzano B, Carpentieri A, Henrissat B, Rossi M, Amoresano A, Moracci M (2014) The identification and molecular characterization of the first archaeal bifunctional exo-β-glucosidase/N-acetyl-β-glucosaminidase demonstrate that family GH116 is made of three functionally distinct subfamilies. Biochim Biophys Acta (BBA) (General Subjects) 1840:367–377CrossRefGoogle Scholar
- Gerday C, Glansdorff N (2007) Physiology and biochemistry of extremophiles. ASM Press, WashingtonGoogle Scholar
- Mir B, Myburg, A, Mizrachi E, Cowan DA (2017) In planta expression of hyperthermophilic enzymes as a strategy for accelerated lignocellulosic digestion. Sci Rep Manuscr (in press)Google Scholar
- Pires VM et al (2017) Stability and ligand promiscuity of type A carbohydrate-binding modules are illustrated by the structure of Spirochaeta thermophila StCBM64C. J Biol Chem M116:767541Google Scholar
- Reetz MT (2017) Recent advances in directed evolution of stereoselective enzymes. In: Directed enzyme evolution: advances and applications. Springer International Publishing, pp 69–99. https://doi.org/10.1007/978-3-319-50413-1_3
- Sainz-Polo MA, González B, Menéndez M, Pastor FJ, Sanz-Aparicio J (2015) Exploring multimodularity in plant cell wall deconstruction: structural and functional analysis of Xyn10C containing the CBM22-1-CBM22-2 tandem. J Biol Chem M115:659300Google Scholar
- Smart M, Huddy RJ, Cowan DA, Trindade M (2017) Liquid phase multiplex high-throughput screening of metagenomic libraries using p-nitrophenyl-linked substrates for accessory lignocellulosic enzymes metagenomics. Methods Protoc 1539:219–228Google Scholar
- Traxlmayr MW, Shusta EV (2017) Directed evolution of protein thermal stability using yeast surface display. Synth Antib Methods Protoc 1575:45–65Google Scholar