Biochemical and molecular characterization of a putative endoglucanase in Magnaporthe grisea.
Microbial pathogens secrete an array of cell wall-degrading enzymes to break down the structure of the host cell wall to facilitate colonization of the host tissue. To better understand their role in the pathogenesis, a putative endoglucanase from Magnaporthe grisea was characterized in this paper. SignalP-3.0 analysis indicates that the protein encoded by gene MGG_02532.5 in M. grisea (named MgEGL1 for M. grisea endoglucanase 1) contains a secretory signal peptide. Multiple alignment shows that MgEGL1 has high level of homology to endoglucanases (EC 3.1.1.4) from Aspergillus nidulans and Trichoderma reesei. The three proteins share a conserved catalytic domain, but only the one from T. reesei contains a cellulose binding module. MgEGL1 was constitutively expressed with the highest level in mycelia and the lowest in conidia. Interestingly, the MgEGL1 RNA could be alternatively processed when cultured in vitro and after infection of rice. Expression analysis confirmed that the MgEGL1 is a secreted protein. Its endoglucanase activity was assayed by Congo red plates, and further confirmed by the dinitrosalicylic acid method. The finding in this paper will provide the basis for further determination of the biochemical properties of the endoglucanase protein and its relevant function in fungal pathogenesis.
Zhou
Jie
J
The Key Laboratory of Biopesticide and Chemistry Biology, Ministry of Education, Fujian Agriculture and Forestry University, 350002 Fuzhou, People's Republic of China.
Zheng
Xiang-zi
XZ
Lan
Lan
L
Lin
Chen-zeng
CZ
Wu
Yu-bing
YB
Lin
Xiong-jie
XJ
Ebbole
Daniel
D
Lu
Guo-dong
GD
Wang
Zong-hua
ZH
D000595:Amino Acid Sequence; D002480:Cellulase / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D015971:Gene Expression Regulation, Enzymologic; D015966:Gene Expression Regulation, Fungal; D020082:Magnaporthe / Q000201:enzymology* / Q000235:genetics; D008969:Molecular Sequence Data; D010802:Phylogeny; D016415:Sequence Alignment
D002480:Cellulase