Structure and characteristics of an endo-beta-1,4-glucanase, isolated from Trametes hirsuta, with high degradation to crystalline cellulose.
Trametes hirsuta produced cellulose-degrading enzymes when it was grown in a cellulosic medium such as Avicel or wheat bran. An endo-beta-1,4-glucanase (ThEG) was purified from the culture filtrate, and the gene and the cDNA were isolated. The gene consisted of an open reading frame encoding 384 amino acids, interrupted by 11 introns. The whole sequence showed high homology with that of family 5 glycoside hydrolase. The properties of the recombinant enzyme (rEG) in Aspergillus oryzae were compared with those of the En-1 from Irpex lacteus, which showed the highest homology among all the endoglucanases reported. The rEG activity against Avicel was about 8 times higher than that of En-1 when based on CMC degradation. A remarkable structural difference between the two enzymes was the length of the linker connecting the cellulose-binding domain to the catalytic domain.
Nozaki
Kouichi
K
Department of Chemistry and Material Engineering, Faculty of Engineering, Shinshu University, Japan. knoza@shinshu-u.ac.jp
Seki
Takahiro
T
Matsui
Keiko
K
Mizuno
Masahiro
M
Kanda
Takahisa
T
Amano
Yoshihiko
Y
D000595:Amino Acid Sequence; D020134:Catalytic Domain; D002480:Cellulase / Q000737:chemistry* / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism*; D002482:Cellulose / Q000378:metabolism*; D003460:Crystallization; D018076:DNA, Complementary / Q000737:chemistry / Q000235:genetics; D004271:DNA, Fungal / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification; D004795:Enzyme Stability; D005800:Genes, Fungal; D006863:Hydrogen-Ion Concentration; D007438:Introns; D008969:Molecular Sequence Data; D016366:Open Reading Frames; D020072:Polyporales / Q000201:enzymology*; D017434:Protein Structure, Tertiary; D011994:Recombinant Proteins / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D013379:Substrate Specificity; D013696:Temperature
D018076:DNA, Complementary; D004271:DNA, Fungal; D011994:Recombinant Proteins; D002482:Cellulose; D002480:Cellulase