Cloning and heterogorous expression of EGI gene from Trichoderma viride

To investigate the property and function of endoglucanse(EGⅠ),the transcriptional expression of egⅠ of Trichoderma viride T4 was analyzed by Northern blot during its growth and development in medium with different carbon source.The full length cDNA sequence of egⅠwas obtained by RT-PCR method and the recombinant vector pYES2-egⅠ was constructed.The vector was transformed into Saccharomyces cerevisiae INVSc1 and H158.The results indicated that the egI was expressed strongly when T.viride T4 was grown in liquid medium containing cellulose as carbon source.The expression of egI was the highest in corn stalk medium,and cellobiose also induced the expression of egI,but no signal was detected in glucose or fructose medium.The ORF of egI was 1 377 bp encoding a protein of 459 amino acids and belonged to glycosyl hydrolase family 7 having cellulose binding-domain and catalytic-domain.egI was a kind of secreted protein because there was signal peptide in the amino acid sequence.The egI transcription of transformants reached highest at 48 hours and a peak recombinant enzyme activity was 0.081 6 U/mL at 60 hours,the recombinant enzyme of EG I of INVSc1 improved 32.5% than that of H158.