RT Journal Article SR Electronic(1) A1 Hu, Nien-Tai A1 Hung, Ming-Ni A1 Huang, A-Min A1 Tsai, Huei-Fung A1 Yang, Bih-Ying A1 Chow, Teh-Yuan A1 Tseng, Yi-HsiungYR 1992 T1 Molecular cloning, characterization and nucleotide sequence of the gene for secreted α-amylase from Xanthomonas campestris pv. campestris JF Microbiology, VO 138 IS 8 SP 1647 OP 1655 DO https://doi.org/10.1099/00221287-138-8-1647 PB Microbiology Society, SN 1465-2080, AB α-Amylase (1,4-α-D-glucan glucanohydrolase, EC 3.2.1.1) of apparent molecular mass 45 kDa was secreted by Xanthomonas campestris pv. campestris grown in medium containing starch or maltose. We isolated its structural gene from a recombinant λ library and located it on a 2.7 kb DNA fragment. Nucleotide sequencing of the fragment revealed a potential ORF encoding a protein of 475 amino acid residues, including a potential signal sequence of 35 amino acids. The signal processing site was confirmed by N-terminal amino acid sequence analysis of the exported α-amylase. The deduced amino acid sequence of the mature protein is very similar to that of the α-amylase of Aeromonas hydrophila. It also contains all four amino acid sequences highly conserved in the α-amylases from a wide range of organisms. Expression of the amy gene in Escherichia coli was poor from its own promoter, but was enhanced by the upstream promoter on the vector. The α-amylase synthesized in E. coli was located in the periplasm., UL https://www.microbiologyresearch.org/content/journal/micro/10.1099/00221287-138-8-1647