■ 基本信息

■ 质粒属性

■ 质粒简介

A genomic library of Bacillus lyticus was constructed in lambda GEM 11 vector and screened for the xylanase gene using Congo red plate assay. A 16-kb fragment containing the xylanase gene was obtained which was further subcloned using Mbo I partial digestion in an E. coli pUC 19 vector. A 1.3-kb sub-fragment was obtained which coded for a xylanase gene of Mr 23,650 Da. This fragment was sequenced and the homology was checked with known xylanases. The maximum homology was 97%, which was obtained with an endo xylanase gene from Bacillus species at the DNA level, while the translated sequence showed only one amino acid change from alanine to serine at position number 102. Expression was checked in E. coli, using the native promoter, and an extracellular activity of 5.25 U/mL was obtained. Cloning of the gene was done in Bacillus subtilis using a shuttle vector pHB 201, which resulted in increasing the basal level xylanase activity from 14.02 to 22.01 U/mL.

■ 质粒图谱

■ 质粒序列

质粒序列可参考（具体以测序为准）下载：ZK1022pHB201枯草胞内质粒.txt

质粒只保证关键序列正确，不保证表达效果。