来自劳氏芽孢杆菌PL236的多个内切-β-1,4-葡聚糖酶编码基因及celB基因的特性分析

Multiple endo-beta-1,4-glucanase-encoding genes from Bacillus lautus PL236 and characterization of the celB gene.

作者信息

Jørgensen P L, Hansen C K

机构信息

Department of Microbiology, Technical University of Denmark, Lyngby.

出版信息

Gene. 1990 Sep 1;93(1):55-60. doi: 10.1016/0378-1119(90)90135-e.

DOI:10.1016/0378-1119(90)90135-e

PMID:2227426

Abstract

A Bacillus lautus strain was isolated from compost by its ability to degrade microcrystalline Avicel cellulose and acid-swollen cellulose. Three DNA fragments cloned in Escherichia coli encoded at least four endo-beta-1,4-glucanases (EG), of which at least two were contained on one DNA fragment. Another fragment, of 2.5 kb and carrying celB, was cloned in the shuttle-vector plasmid, pJKK3-1, and expressed in E. coli and Bacillus subtilis. The fragment was sequenced and shown to encode a 62-kDa protein, which was found as a 56-kDa mature and active EG in extracts of E. coli and in the supernatant of B. subtilis. The deduced amino acid (aa) sequence has a homology of 37% identical aa on a stretch of 295 aa to EG-E of Clostridium thermocellum. A low level of homology is detected with the Bacillus-type EG.

摘要

通过其降解微晶纤维素和酸溶胀纤维素的能力，从堆肥中分离出一株迟缓芽孢杆菌。在大肠杆菌中克隆的三个DNA片段编码至少四种内切β-1,4-葡聚糖酶（EG），其中至少两种包含在一个DNA片段上。另一个2.5 kb且携带celB的片段被克隆到穿梭载体质粒pJKK3-1中，并在大肠杆菌和枯草芽孢杆菌中表达。对该片段进行测序，结果表明它编码一种62 kDa的蛋白质，在大肠杆菌提取物和枯草芽孢杆菌的上清液中发现其为56 kDa的成熟且有活性的EG。推导的氨基酸（aa）序列在295个aa的片段上与嗜热栖热放线菌的EG-E有37%的同源性。与芽孢杆菌型EG检测到较低水平的同源性。