title: Identification and characterization of a multidomain hyperthermophilic cellulase from an archaeal enrichment.
abstract: Despite extensive studies on microbial and enzymatic lignocellulose degradation, relatively few Archaea are known to deconstruct crystalline cellulose. Here we describe a consortium of three hyperthermophilic archaea enriched from a continental geothermal source by growth at 90 °C on crystalline cellulose, representing the first instance of Archaea able to deconstruct lignocellulose optimally above 90 °C. Following metagenomic studies on the consortium, a 90 kDa, multidomain cellulase, annotated as a member of the TIM barrel glycosyl hydrolase superfamily, was characterized. The multidomain architecture of this protein is uncommon for hyperthermophilic endoglucanases, and two of the four domains of the enzyme have no characterized homologues. The recombinant enzyme has optimal activity at 109 °C, a half-life of 5 h at 100 °C, and resists denaturation in strong detergents, high-salt concentrations, and ionic liquids. Cellulases active above 100 °C may assist in biofuel production from lignocellulosic feedstocks by hydrolysing cellulose under conditions typically employed in biomass pretreatment.
authors: Energy Biosciences Institute, University of California, Berkeley, California 94720, USA.
authors: Joel E
authors: JE
authors: Graham
authors: Melinda E
authors: ME
authors: Clark
authors: Dana C
authors: DC
authors: Nadler
authors: Sarah
authors: S
authors: Huffer
authors: Harshal A
authors: HA
authors: Chokhawala
authors: Sara E
authors: SE
authors: Rowland
authors: Harvey W
authors: HW
authors: Blanch
authors: Douglas S
authors: DS
authors: Clark
authors: Frank T
authors: FT
authors: Robb
mesh_terms: D001105:Archaea / Q000201:enzymology*; D001483:Base Sequence; D002480:Cellulase / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism*; D019295:Computational Biology; D004586:Electrophoresis; D006207:Half-Life; D016013:Likelihood Functions; D056186:Metagenomics; D008957:Models, Genetic; D008969:Molecular Sequence Data; D010802:Phylogeny; D017434:Protein Structure, Tertiary; D017422:Sequence Analysis, DNA; D053719:Tandem Mass Spectrometry; D013696:Temperature
chemical_list: D002480:Cellulase