Sc. Wu et al., PURIFICATION, CLONING AND CHARACTERIZATION OF 2 XYLANASES FROM MAGNAPORTHE-GRISEA, THE RICE BLAST FUNGUS, Molecular plant-microbe interactions, 8(4), 1995, pp. 506-514
Magnaporthe grisea, the fungal pathogen that causes rice blast disease
, secretes two endo-beta-1,4-D-xylanases (E. C. 3.2.1.8) when grown on
rice cell walls as the only carbon source, One of the xylanases, XYN3
3, is a 33-kD protein on sodium dodecyl sulfate-polyacrylamide gel and
accounts for approximately 70% of the endoxylanase activity in the cu
lture filtrate, The second xylanase, XYN22, is a 22-kD protein and acc
ounts for approximately 30% of the xylanase activity, The two proteins
were purified, cloned, and sequenced, XYN33 and XYN22 are both basic
proteins with calculated isoelectric points of 9.95 and 9.71, respecti
vely, The amino acid sequences of XYN33 and XYN22 are not homologous,
but they are similar, respectively, to family F and family G xylanases
from other microorganisms. The genes encoding XYN33 and XYN22, design
ated XYN33 and XYN22, are single-copy in the haploid genome of M. gris
ea and are expressed when M. grisea is grown on rice cell walls or on
oatspelt xylan, but not when grown on sucrose.