Variant cbh i polypeptides

Abstract

In alternative embodiments, the invention provides polypeptides having a lignocellulolytic (lignocellulosic) activity, e.g., a ligninolytic and cellulolytic activity, including, e.g., a glycosyl hydrolase, a cellulase, an endoglucanase, a cellobiohydrolase (cbhl) (e.g., an exo-cellobiohydrolase, e.g., having an 'exo' activity that can processively release cellobiose units β-1,4 glucose-glucose disaccharide), a beta-glucosidase, a xylanase, a mannanse, a xylosidase (e.g., a (β-xylosidase) and/or an arabinofuranosidase activity, polynucleotides encoding these polypeptides, and methods of making and using these polynucleotides and polypeptides. In one embodiment, the invention provides thermostable and thermotolerant forms of polypeptides of the invention. The polypeptides and nucleic acids of the invention are used in a variety of pharmaceutical, agricultural and industrial contexts; for example, as enzymes for the bioconversion of a biomass, e.g., lignocellulosic residues, into fermentable sugars, where in one aspect these sugars are used as a chemical feedstock for the production of ethanol and fuels, e.g., biofuels, e.g., synthetic liquid or gas fuels, including ethanol, methanol and the like.