摘要
芽孢杆菌CY1-3株基因组DNA经Sau3A Ⅰ部分消化后回收2～7 kb片段,构建了部分文库.通过刚果红染色鉴定,筛选出6个纤维素酶基因的阳性克隆子,经酶切鉴定为同一克隆子,命名为pGJc-1.经测序分析,该片段包含一个由1 593个核苷酸组成的开放阅读框（ORF）,命名为celC.经推导,celC基因编码由一531个氨基酸残基组成的CelC蛋白.氨基酸序列分析表明,CelC蛋白的氨基酸序列与多种细菌的β-1,4-内切葡聚糖酶具有很高的同源性.粗酶液的SDSPAGE分析表明,celC基因在大肠杆菌中所表达的CelC蛋白具有纤维素酶活力,其分子质量约为58 ku.
A genomic library of Bacillus sp. CY1-3 strain was constructed in Escherichia coli strain DHSa by ligating BamH Ⅰ -digested pBluSKM vector with 2-7 kb Sau3A Ⅰ -digested genomic DNA from Bacillus sp. CY1-3 strain. Six clones expressing carboxymethylcellulase（CMCase） activity were isolated from nearly 100 000 clones by screening the library with Congo red dying. These clones were identified to be the same clone by restriction endonuclease digestion,and it was designated as pGJc-1. The 2-7 kb fragment contained a 1 593 bp ORF,named celC,which codes 531 amino acid residues. Compared the amino acid sequence of CelC with those available in GenBank,it was highly identical to endo-β-1,4-glucanase from Bacillus strains. SDS-PAGE analysis showed that protein expressed from gene celC in E. coli had cellulase activity,and its molecular weight was 58.0 ku approximately.
出处
《中国兽医科学》
CAS
CSCD
北大核心
2006年第12期961-966,共6页
Chinese Veterinary Science
基金
西北民族大学中青年基金项目(科技发200624号
200528号)
