Nucleotide sequence and analysis of the Vibrio alginolyticus sucrase gene (scrB)

The nucleotide sequence of a 2.119-kb DNA fragment containing the Vibrio alginolyticus sucrase gene (scrB) was determined. The complete sequence (484 aa residues) of the sucrase was deduced and homology was detected between the sucrase enzymes from V. alginolyticus and the Gram-positive bacteria Bacillus subtilis and Streptococcus mutans. In Escherichia coli cells the cloned V. alginolyticus sucrase is translocated to the periplasm. Transposon phoA mutagenesis experiments strongly suggested that V. alginolyticus sucrase in E. coli is not exported across the cytoplasmic membrane by means of a typical signal sequence.