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Loosenin, a novel protein with cellulose-disrupting activity from Bjerkandera adusta.

Quiroz-Castañeda RE, Martínez-Anaya C, Cuervo-Soto LI, Segovia L, Folch-Mallol JL - Microb. Cell Fact. (2011)

Bottom Line: 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 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.

View Article: PubMed Central - HTML - PubMed

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.

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.

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loos1 gene structure. (a) Map of the loos1 gene organization. Exons are shown as arrows and introns as lines, drawn to scale. (b) The predicted core of the promoter region containing a TATA box at -25 is distinguished in large letters, as well as the nucleotide indicating the predicted site of transcription initiation (TSS). Untranslated regions, 5' and 3', and a possible polyadenylation signal are shown flanking the coding sequence of loos1. Introns I, II and III are shown in lowercase italic letters, to compare to the coding sequence of loos1.
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Figure 1: loos1 gene structure. (a) Map of the loos1 gene organization. Exons are shown as arrows and introns as lines, drawn to scale. (b) The predicted core of the promoter region containing a TATA box at -25 is distinguished in large letters, as well as the nucleotide indicating the predicted site of transcription initiation (TSS). Untranslated regions, 5' and 3', and a possible polyadenylation signal are shown flanking the coding sequence of loos1. Introns I, II and III are shown in lowercase italic letters, to compare to the coding sequence of loos1.

Mentions: loos1 genomic DNA sequence includes three introns I, II and III, two of which (introns II and III) exhibit the canonical 5'-GT....AG-3' donor-acceptor pairs. Intron lengths are 55, 53 and 52 nt, respectively, in agreement with the average intron size of filamentous fungi (50-70 bp), and account for 160 extra nucleotides relative to the cDNA (Figure 1a). The 5' and 3' UTRs are predicted to consist of 98 and 100 nucleotides respectively (Figure 1b).


Loosenin, a novel protein with cellulose-disrupting activity from Bjerkandera adusta.

Quiroz-Castañeda RE, Martínez-Anaya C, Cuervo-Soto LI, Segovia L, Folch-Mallol JL - Microb. Cell Fact. (2011)

loos1 gene structure. (a) Map of the loos1 gene organization. Exons are shown as arrows and introns as lines, drawn to scale. (b) The predicted core of the promoter region containing a TATA box at -25 is distinguished in large letters, as well as the nucleotide indicating the predicted site of transcription initiation (TSS). Untranslated regions, 5' and 3', and a possible polyadenylation signal are shown flanking the coding sequence of loos1. Introns I, II and III are shown in lowercase italic letters, to compare to the coding sequence of loos1.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3050684&req=5

Figure 1: loos1 gene structure. (a) Map of the loos1 gene organization. Exons are shown as arrows and introns as lines, drawn to scale. (b) The predicted core of the promoter region containing a TATA box at -25 is distinguished in large letters, as well as the nucleotide indicating the predicted site of transcription initiation (TSS). Untranslated regions, 5' and 3', and a possible polyadenylation signal are shown flanking the coding sequence of loos1. Introns I, II and III are shown in lowercase italic letters, to compare to the coding sequence of loos1.
Mentions: loos1 genomic DNA sequence includes three introns I, II and III, two of which (introns II and III) exhibit the canonical 5'-GT....AG-3' donor-acceptor pairs. Intron lengths are 55, 53 and 52 nt, respectively, in agreement with the average intron size of filamentous fungi (50-70 bp), and account for 160 extra nucleotides relative to the cDNA (Figure 1a). The 5' and 3' UTRs are predicted to consist of 98 and 100 nucleotides respectively (Figure 1b).

Bottom Line: 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 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.

View Article: PubMed Central - HTML - PubMed

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.

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.

Show MeSH
Related in: MedlinePlus