胡萝卜软腐欧文氏菌胡萝卜软腐亚种LY34的一个羧甲基纤维素酶基因celB的克隆、特性分析及其与celA的比较

Cloning and characterization of a CMCase gene, celB, of Erwinia carotovora subsp. carotovora LY34 and its comparison to celA.

作者信息

Woo Park Y, Tech Lim S, Dae Yun H

机构信息

Genetic Engineering Institute, Gyeongsang National University, Chinju, Korea.

出版信息

Mol Cells. 1998 Jun 30;8(3):280-5.

PMID:9666464

Abstract

The phytopathogenic Erwinia carotovora subsp. carotovora (Ecc) LY34 secretes multiple isozymes of the plant cell wall-disintegrating enzyme endoglucanase. We isolated a second cel gene encoding CMCase in Ecc LY34. A 3.7 kb fragment was subcloned to generate pLYCB100 (celB). The structural organization of the celB gene consists of an open reading frame (ORF) of 792 bp encoding 264 264 amino acid residues with a calculated molecular weight of 29,890 Da The predicted amino acid sequence of CelB is very similar to that of CelS of another Ecc strain, SCRI193, but completely different from that of the CelA of Ecc LY34. It belongs to the glycosyl hydrolase family 12 based on amino acid sequence similarities. It is optimally active at pH 6.8 with an optimal temperature of about 50 degrees C. The CMCase activity of CelB is about 60% of that of CelA.

摘要

植物病原胡萝卜软腐欧文氏菌胡萝卜软腐亚种（Ecc）LY34分泌多种植物细胞壁降解酶内切葡聚糖酶的同工酶。我们在Ecc LY34中分离出了第二个编码羧甲基纤维素酶（CMCase）的cel基因。一个3.7 kb的片段被亚克隆以产生pLYCB100（celB）。celB基因的结构组织由一个792 bp的开放阅读框（ORF）组成，编码264个氨基酸残基，计算分子量为29,890 Da。CelB的预测氨基酸序列与另一个Ecc菌株SCRI193的CelS非常相似，但与Ecc LY34的CelA完全不同。基于氨基酸序列相似性，它属于糖基水解酶家族12。它在pH 6.8时活性最佳，最适温度约为50℃。CelB的CMCase活性约为CelA的60%。