고초균으로부터 β - glucanase 유전자의 분리 및 대장균에서의 발현

Abstract

A gene coding for β-glucanase which can specifically hydorlyze barley β-glucan and lichenan was isolated from Bacillus subtilis ATCC6633 by molecular cloning using a plasmid vector pBR325. 2.1 Kb BamHI-HindIII DNA fragment conferred β-glucanase activity on Escherichia coli HB101 and 1.7 Kb PstI DNA fragment included in 2.1 Kb fragment gave rise to β-glucanase producing colonies, while its expression depended upon its inserting orientation in pUC9. This gene directed efficiently the synthesis of β-glucanase in E. coli. Up to 2496 of total activity was found outside of the cells. Fine restriction map was also constructed for further sequencing analysis. The transcriptional direction of cloned β-glucanase gene was determined and its putative functional unit could be deducted from the molecular weight of β-glucanase and by deletion mapping.