Heterologous expression and characterization of an endoglucanase from a symbiotic protist of the lower termite, Reticulitermes speratus.
RsSymEG, an endoglucanase of glycosyl hydrolase family (GHF) 7 encoded by a transcript isolated from the symbiotic protist of the termite Reticulitermes speratus, is expressed in Aspergillus oryzae. Interestingly, purified RsSymEG1 has a relatively higher specific activity (603 micromol min(-1) mg(-1) protein) and V(max) value (769.6 unit/mg protein) than previously reported data for GHF7 endoglucanase of Trichoderma ressei. It also has the same K(m) value (1.97 mg/ml) with Clostridium cellulolyticum enzymes that contain cellulose binding module, a property indicative of high affinity to substrate, though no cellulose binding module is found within it. Thin-layer chromatography analysis revealed that RsSymEG1 preferentially hydrolyzes the beta-1,4-cellulosic linkage of cellodextrins into cellobiose and glucose.
Todaka
Nemuri
N
Laboratory of Environmental Molecular Biology, RIKEN, 1-7-29 Suehiro-cho, Tsurumi-ward, Kanagawa 230-0045, Japan.
Lopez
Crisanto M
CM
Inoue
Tetsushi
T
Saita
Kanako
K
Maruyama
Jun-Ichi
J
Arioka
Manabu
M
Kitamoto
Katsuhiko
K
Kudo
Toshiaki
T
Moriya
Shigeharu
S
D000595:Amino Acid Sequence; D000818:Animals; D001236:Aspergillus oryzae / Q000235:genetics; D002480:Cellulase / Q000235:genetics* / Q000378:metabolism; D002855:Chromatography, Thin Layer; D015870:Gene Expression; D006863:Hydrogen-Ion Concentration; D020049:Isoptera / Q000382:microbiology; D007700:Kinetics; D008969:Molecular Sequence Data; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000378:metabolism; D016415:Sequence Alignment; D013379:Substrate Specificity; D013559:Symbiosis
D011994:Recombinant Proteins; D002480:Cellulase