Thermostability in endoglucanases is fold-specific
1 Department of Genetics, Development and Cell Biology, Iowa State University, Ames, IA 50011, USA
2 Department of Physics, Indiana University-Purdue University Indianapolis, Indianapolis, IN 46202, USA
3 Biosafety Institute for Genetically Modified Agricultural Products and Department of Agronomy, Iowa State University, Ames, IA 50011, USA
4 U.S. Department of Agriculture - Agricultural Research Service, Corn Insects and Crop Genomics Research Unit, Ames, IA, 50011, USA
5 Bioinformatics and Computational Biology Program, Iowa State University, Ames, IA, 50011, USA
BMC Structural Biology 2011, 11:10 doi:10.1186/1472-6807-11-10Published: 3 February 2011
Endoglucanases are usually considered to be synergistically involved in the initial stages of cellulose breakdown-an essential step in the bioprocessing of lignocellulosic plant materials into bioethanol. Despite their economic importance, we currently lack a basic understanding of how some endoglucanases can sustain their ability to function at elevated temperatures required for bioprocessing, while others cannot. In this study, we present a detailed comparative analysis of both thermophilic and mesophilic endoglucanases in order to gain insights into origins of thermostability. We analyzed the sequences and structures for sets of endoglucanase proteins drawn from the Carbohydrate-Active enZymes (CAZy) database.
Our results demonstrate that thermophilic endoglucanases and their mesophilic counterparts differ significantly in their amino acid compositions. Strikingly, these compositional differences are specific to protein folds and enzyme families, and lead to differences in intramolecular interactions in a fold-dependent fashion.
Here, we provide fold-specific guidelines to control thermostability in endoglucanases that will aid in making production of biofuels from plant biomass more efficient.