Kraiwattanapong J, Ooi T, Kinoshita S
Department of Molecular Chemistry, Faculty of Engineering, Hokkaido Graduate University, Japan.
Biosci Biotechnol Biochem. 1997 Nov;61(11):1853-7. doi: 10.1271/bbb.61.1853.
Pseudomonas sp. OS-ALG-9 produces several kinds of alginate-degrading enzymes both intra- and extracellularly. As a second alginate lyase of this bacterium, the gene encoding alyII has been cloned in Escherichia coli JM109 by shotgun techniques and then sequenced. The alyII gene has an open reading frame of 2141 bp encoding 713 amino acid residues with a calculated molecular mass of 79,803 Da. The deduced amino acid sequence did not show any extensive similarity with those of other known alginate lyases, however, hydrophobic cluster analysis showed that alyII belonged to class 3 of alginate lyases. The alginate lyase from E. coli harboring the alyII gene showed a single active band, which coincided with one of four major alginate lyases from the crude cell extracts of Pseudomonas sp. OS-ALG-9 on a zymogram.
假单胞菌属OS-ALG-9在细胞内和细胞外均产生多种藻酸盐降解酶。作为该细菌的第二种藻酸盐裂解酶，编码alyII的基因已通过鸟枪法克隆到大肠杆菌JM109中，随后进行了测序。alyII基因有一个2141 bp的开放阅读框，编码713个氨基酸残基，计算分子量为79,803 Da。推导的氨基酸序列与其他已知藻酸盐裂解酶的序列没有任何广泛的相似性，然而，疏水簇分析表明alyII属于藻酸盐裂解酶的第3类。携带alyII基因的大肠杆菌产生的藻酸盐裂解酶在酶谱上显示出一条单一的活性带，这与假单胞菌属OS-ALG-9粗细胞提取物中的四种主要藻酸盐裂解酶之一一致。
