Cloning and nucleotide sequence of an extracellular alpha-amylase gene from Aeromonas hydrophila MCC-1.
A gene encoding the extracellular alpha-amylase of Aeromonas hydrophila MCC-1 was cloned and expressed using its own promoter on the recombinant plasmid pCA101. Subcellular fractionation of Escherichia coli JA221 carrying pCA101 revealed that approximately 60% of the amylase activity was localized in the periplasmic space. The extracellular amylase was purified to homogeneity, identified as an alpha-type and its amino-terminal sequence was determined. Nucleotide sequence analysis predicted a 443 amino acid ORF and 24 amino acids at the amino terminus of the sequence that are not found in the secreted protein. This 24 amino acid sequence has many of the characteristics common to known signal peptides. The predicted amino acid sequence has considerable similarity with mammalian, invertebrate and Streptomycete alpha-amylases. Most of the amino acid residues that are involved in catalytic activity, substrate binding and calcium binding in several alpha-amylases were also present in A. hydrophila alpha-amylase at the corresponding positions.
Chang
M C
MC
Department of Biochemistry Medical College, National Cheng Kung University, Tainan, Taiwan, Republic of China.
Chang
J C
JC
Chen
J P
JP
D016980:Aeromonas hydrophila / Q000201:enzymology* / Q000235:genetics*; D000595:Amino Acid Sequence; D001483:Base Sequence; D003001:Cloning, Molecular; D003062:Codon / Q000235:genetics; D004269:DNA, Bacterial / Q000235:genetics; D005110:Extracellular Space / Q000201:enzymology; D005798:Genes, Bacterial; D008969:Molecular Sequence Data; D017386:Sequence Homology, Amino Acid; D000516:alpha-Amylases / Q000235:genetics* / Q000302:isolation & purification
D003062:Codon; D004269:DNA, Bacterial; D000516:alpha-Amylases