Cloning, characterization and heterologous expression of the first Penicillium echinulatum cellulase gene.
OBJECTIVE
Penicillium echinulatum is effective for bioconversion processes. However, nothing is known about the molecular biology of its cellulolytic system. We describe for the first time the isolation, cloning and expression of a P. echinulatum cellulase cDNA (Pe-egl1) encoding a putative endoglucanase.


RESULTS
Pe-egl1 cDNA was identified from random sequencing of a P. echinulatum cDNA library. The deduced EGL1 protein possibly belongs to the glycosyl hydrolase family 5A, with 387 amino acid residues and strong similarity with other fungal endoglucanases. The cDNA was heterologously expressed in Pichia pastoris. The recombinant EGL1 secreted by a Pic. pastoris recombinant strain revealed the characteristics of particular interest: an optimal activity over a broad pH range (5.0-9.0), and an optimal temperature of 60 degrees C. The recombinant EGL1 also showed high thermostability (84% of residual activity after 1 h of pre-incubation at 70 degrees C). Calcium exerted a strong stimulatory effect over EGL1 activity.


CONCLUSIONS
Altogether, these results point to the potential application of this P. echinulatum endoglucanase in cellulose processing industries, particularly the textile one because of its biochemical properties.


CONCLUSIONS
The characterization and heterologous expression of the first P. echinulatun cDNA inaugurates the exploitation of this potential industrial micro-organism.
Department of Cellular Biology, Institute of Biological Sciences, University of Brasília, Brasília-DF, Brazil.
M R
MR
Rubini
A J P
AJ
Dillon
C M
CM
Kyaw
F P
FP
Faria
M J
MJ
Poças-Fonseca
I
I
Silva-Pereira
D000595:Amino Acid Sequence; D001483:Base Sequence; D002412:Cations / Q000494:pharmacology; D002480:Cellulase / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D002482:Cellulose / Q000378:metabolism; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000235:genetics; D004789:Enzyme Activation / Q000187:drug effects; D004791:Enzyme Inhibitors / Q000494:pharmacology; D015966:Gene Expression Regulation, Fungal; D005800:Genes, Fungal / Q000235:genetics; D006863:Hydrogen-Ion Concentration; D008969:Molecular Sequence Data; D010407:Penicillium / Q000201:enzymology* / Q000235:genetics*; D010843:Pichia / Q000235:genetics; D011994:Recombinant Proteins / Q000378:metabolism; D016415:Sequence Alignment; D013379:Substrate Specificity; D013696:Temperature
D002412:Cations; D018076:DNA, Complementary; D004791:Enzyme Inhibitors; D011994:Recombinant Proteins; D002482:Cellulose; D002480:Cellulase