Molecular cloning, characterization, and nucleotide sequence of an extracellular amylase gene from Aeromonas hydrophila

Open Access
Publisher Website
Google Scholar
Abstract
The structural gene for excreted amylase from Aeromonas hydrophila JMP636 has been cloned within a 2.1-kilobase SmaI fragment of DNA. The amylase gene is transcribed from its own promoter in Escherichia coli, producing a gene product of Mr 49,000. The amylase gene product is secreted to the periplasm of E. coli; however, it is not excreted. Nucleotide sequencing revealed an open reading frame of 1,392 base pairs corresponding to a protein of 464 amino acid residues. A potential signal peptide of 21 amino acid residues is present at the NH2 terminal of the predicted protein. Three regions of homology with other procaryotic and eucaryotic alpha-amylases were detected within the predicted amino acid sequence.