Email updates

Keep up to date with the latest news and content from BMC Microbiology and BioMed Central.

Open Access Highly Accessed Database

GASdb: a large-scale and comparative exploration database of glycosyl hydrolysis systems

Fengfeng Zhou12, Huiling Chen1 and Ying Xu12*

Author Affiliations

1 Computational Systems Biology Laboratory, Department of Biochemistry and Molecular Biology, and Institute of Bioinformatics, University of Georgia, Athens, GA 30602, USA

2 BioEnergy Science Center, Oak Ridge, TN, 37831, USA

For all author emails, please log on.

BMC Microbiology 2010, 10:69  doi:10.1186/1471-2180-10-69

Published: 4 March 2010



The genomes of numerous cellulolytic organisms have been recently sequenced or in the pipeline of being sequenced. Analyses of these genomes as well as the recently sequenced metagenomes in a systematic manner could possibly lead to discoveries of novel biomass-degradation systems in nature.


We have identified 4,679 and 49,099 free acting glycosyl hydrolases with or without carbohydrate binding domains, respectively, by scanning through all the proteins in the UniProt Knowledgebase and the JGI Metagenome database. Cellulosome components were observed only in bacterial genomes, and 166 cellulosome-dependent glycosyl hydrolases were identified. We observed, from our analysis data, unexpected wide distributions of two less well-studied bacterial glycosyl hydrolysis systems in which glycosyl hydrolases may bind to the cell surface directly rather than through linking to surface anchoring proteins, or cellulosome complexes may bind to the cell surface by novel mechanisms other than the other used SLH domains. In addition, we found that animal-gut metagenomes are substantially enriched with novel glycosyl hydrolases.


The identified biomass degradation systems through our large-scale search are organized into an easy-to-use database GASdb at webcite, which should be useful to both experimental and computational biofuel researchers.