4M1R

Structure of a novel cellulase 5 from a sugarcane soil metagenomic library

Summary for 4M1R

• Entry DOI: 10.2210/pdb4m1r/pdb
• Descriptor: Cellulase 5, 2-AMINO-2-HYDROXYMETHYL-PROPANE-1,3-DIOL (3 entities in total)
• Functional Keywords: tim barrel, cellulase, hydrolase
• Biological source: soil metagenome (sugarcane soil metagenome)
• Total number of polymer chains: 2
• Total formula weight: 63788.47

Authors

Paiva, J.H.,Alvarez, T.M.,Cairo, J.P.,Paixao, D.A.,Almeida, R.A.,Tonoli, C.C.C.,Ruiz, D.M.,Ruller, R.,Santos, C.R.,Squina, F.M.,Murakami, M.T. (deposition date: 2013-08-03, release date: 2014-02-05, Last modification date: 2024-02-28)

Primary citation

Alvarez, T.M.,Paiva, J.H.,Ruiz, D.M.,Cairo, J.P.,Pereira, I.O.,Paixao, D.A.,de Almeida, R.F.,Tonoli, C.C.,Ruller, R.,Santos, C.R.,Squina, F.M.,Murakami, M.T.
Structure and function of a novel cellulase 5 from sugarcane soil metagenome.
Plos One, 8:e83635-e83635, 2013

PubMed Abstract: Cellulases play a key role in enzymatic routes for degradation of plant cell-wall polysaccharides into simple and economically-relevant sugars. However, their low performance on complex substrates and reduced stability under industrial conditions remain the main obstacle for the large-scale production of cellulose-derived products and biofuels. Thus, in this study a novel cellulase with unusual catalytic properties from sugarcane soil metagenome (CelE1) was isolated and characterized. The polypeptide deduced from the celE1 gene encodes a unique glycoside hydrolase domain belonging to GH5 family. The recombinant enzyme was active on both carboxymethyl cellulose and β-glucan with an endo-acting mode according to capillary electrophoretic analysis of cleavage products. CelE1 showed optimum hydrolytic activity at pH 7.0 and 50 °C with remarkable activity at alkaline conditions that is attractive for industrial applications in which conventional acidic cellulases are not suitable. Moreover, its three-dimensional structure was determined at 1.8 Å resolution that allowed the identification of an insertion of eight residues in the β8-α8 loop of the catalytic domain of CelE1, which is not conserved in its psychrophilic orthologs. This 8-residue-long segment is a prominent and distinguishing feature of thermotolerant cellulases 5 suggesting that it might be involved with thermal stability. Based on its unconventional characteristics, CelE1 could be potentially employed in biotechnological processes that require thermotolerant and alkaline cellulases.

PubMed: 24358302
DOI: 10.1371/journal.pone.0083635

Experimental method

X-RAY DIFFRACTION (1.8 Å)