Takashima S, Nakamura A, Masaki H, Uozumi T
Department of Biotechnology, Faculty of Agriculture, University of Tokyo, Japan.
Biosci Biotechnol Biochem. 1997 Feb;61(2):245-50. doi: 10.1271/bbb.61.245.
The egl2 gene coding a thermostable endoglucanase (EGL2) was cloned from Humicola grisea. The DNA sequence of egl2 predicted two putative introns in the coding region. The deduced amino acid sequence of EGL2 was 388 amino acids in length and showed 99.5% identity with the H. insolens CMC 3. In addition to TATA box and CAAT motifs, putative CREA binding sites were observed in the 5' upstream region of the egl2 gene. The egl2 gene was expressed in Aspergillus oryzae, and EGL2 was purified. EGL2 produced by A. oryzae showed a high activity toward carboxymethyl cellulose. The optimal temperature of EGL2 was 75 degrees C, and EGL2 had more than 80% residual activity after heating up to 75 degrees C for 10 min. This is the first report of enzymatic properties of the EGL2-type thermostable cellulase homologs from Humicola.
从灰腐质霉中克隆出编码耐热内切葡聚糖酶（EGL2）的egl2基因。egl2的DNA序列预测在编码区有两个推定的内含子。推导的EGL2氨基酸序列长度为388个氨基酸，与特异腐质霉CMC 3的同一性为99.5%。除TATA盒和CAAT基序外，在egl2基因的5'上游区域观察到推定的CREA结合位点。egl2基因在米曲霉中表达，并对EGL2进行了纯化。米曲霉产生的EGL2对羧甲基纤维素具有高活性。EGL2的最适温度为75℃，在75℃加热10分钟后EGL2具有超过80%的残余活性。这是关于来自腐质霉的EGL2型耐热纤维素酶同源物酶学性质的首次报道。
