经典型霍乱弧菌毒素基因的核苷酸序列分析及其与ELTOR型的比较

Nucleotide Sequence Analysis of the Gene Encoding the Classical Biotype Ⅴ. Cholera Toxin and its Comparison with ELTOR Biotype

本文首次报导了经典型霍乱弧菌569B株毒素基因的全部核苷酸序列,并与其他经典型和ELTOR型毒素基因的核苷酸序列以及由此推导的氨基酸序列进行比较。发现此两型毒素基因的A亚基核苷酸序列完全相同,而B亚基有2至3个碱基的差别,从而导致相应氨基酸的改变,它们分别位于第18、47和54位氨基酸残基。

The complete nucleotide sequence of the DNA encoding A and B subunits from V. cholera classical biotype strain 569B has first been reported, and the comparison of nucleotide sequence and deduced amino acid sequence was made with other classical and ELTOR strains reported so far. Our results show that the nucleotide sequence of A subunit are completely identical in both biotypes. While 2 to 3 base changes are found between them which results in alteration of the corresponding amino acids. They are located at residues 18, 47 and 54 respectively.