title: Loosenin, a novel protein with cellulose-disrupting activity from Bjerkandera adusta.
abstract: BACKGROUND
  Expansins and expansin-like proteins loosen cellulose microfibrils, possibly through the rupture of intramolecular hydrogen bonds. Together with the use of lignocellulolytic enzymes, these proteins are potential molecular tools to treat plant biomass to improve saccharification yields.
  
  
  RESULTS
  Here we describe a new type of expansin-related fungal protein that we have called loosenin. Its corresponding gene, loos1, from the basidiomycete Bjerkandera adusta, was cloned and heterologously expressed in Saccharomyces cerevisiae. LOOS1 is distantly related to plant expansins through the shared presence of a DPBB domain, however domain II found in plant expansins is absent. LOOS1 binds tightly to cellulose and chitin, and we demonstrate that cotton fibers become susceptible to the action of a commercial cellulase following treatment with LOOS1. Natural fibers of Agave tequilana also become susceptible to hydrolysis by cellulases after loosenin treatment.
  
  
  CONCLUSIONS
  LOOS1 is a new type of protein with disrupting activity on cellulose. LOOS1 binds polysaccharides, and given its enhancing properties on the action of hydrolytic enzymes, LOOS1 represents a potential additive in the production of fermentable sugars from lignocellulose.
authors.affiliation: Laboratorio de Biología Molecular de Hongos, Centro de Investigación en Biotecnología, Universidad Autónoma del Estado de Morelos, Avenida Universidad 1001 Col, Chamilpa, Cuernavaca 62209, Morelos, Mexico.
authors.forename: Rosa E
authors.initials: RE
authors.lastname: Quiroz-Castañeda
authors.forename: Claudia
authors.initials: C
authors.lastname: Martínez-Anaya
authors.forename: Laura I
authors.initials: LI
authors.lastname: Cuervo-Soto
authors.forename: Lorenzo
authors.initials: L
authors.lastname: Segovia
authors.forename: Jorge L
authors.initials: JL
authors.lastname: Folch-Mallol
mesh_terms: D000595:Amino Acid Sequence; D002482:Cellulose / Q000737:chemistry / Q000378:metabolism*; D002686:Chitin / Q000737:chemistry / Q000378:metabolism; D003001:Cloning, Molecular; D055453:Coriolaceae / Q000378:metabolism*; D005656:Fungal Proteins / Q000235:genetics / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D008969:Molecular Sequence Data; D011485:Protein Binding; D012441:Saccharomyces cerevisiae / Q000378:metabolism; D013696:Temperature
chemical_list: D005656:Fungal Proteins; D002686:Chitin; D002482:Cellulose