The Gene Cloning And Singal Peptide Determination Of GH10 Family Xylanase From Aspergillus Niger

The mRNA in A.niger was extracted, reverse transcription, and then four GH10 family xylanase genes was cloned by primers which designed from homology alignment and software prediction. They were transferred into pET20b vector and finally activated xylanase in E. coli BL21 (DE3) was received.Then the impact of the two different signal peptides on their activity was discovered:the two have obvious different nature. Such as X3 obtained from software prediction (by SignalP), has low optimal temperature 35℃,and X1 has no activity at 50℃;otherwise X2 and X4 obtained from homology,it is 50℃,45℃respectively. Research into crude enzyme’s(X2、X3 and X4) nature:the optimal pH of all three is 5.2, and the pH stability have not many changes;also, the nature of pure proteins X3 and X4 which have His tags are like their crude counterparts. So,the right signal sites is from 1st to 25th.In conclusion, we have got a new GH10 family xylanase gene, at the same time, we have found the right signal peptide of this enzyme by the two methods of peptide prediction.