@article{mbs:/content/journal/micro/10.1099/00221287-133-11-3271, author = "Sohma, Akira and Fujita, Tomoo and Yamane, Kunio", title = "Protein Processing to Form Extracellular Thermostable α-Amylases from a Gene Fused in a Bacillus subtilis Secretion Vector", journal= "Microbiology", year = "1987", volume = "133", number = "11", pages = "3271-3277", doi = "https://doi.org/10.1099/00221287-133-11-3271", url = "https://www.microbiologyresearch.org/content/journal/micro/10.1099/00221287-133-11-3271", publisher = "Microbiology Society", issn = "1465-2080", type = "Journal Article", abstract = "SUMMARY: A thermostable α-amylase gene (amyT631) from Bacillus stearothermophilus A631 was cloned into pBR322 and recloned into pUB110: the resulting plasmid was designated pTUB607. To investigate the processing from preproenzyme to mature enzyme, amyT631 from pTUB607, after digestion with BAL31, was introduced into the B. subtilis α-amylase secretion vector pTUB285. Three chimaeric plasmids, pTUB613, pTUB616, and pTUB617, were isolated. The fused α-amylases expressed from the three plasmids seemed to be synthesized as preproenzymes. From analysis of the NH2-terminal amino acid sequences of purified extracellular α-amylases, the precursors of the fused enzymes appeared to be cleaved at first between amino acids 31 and 32 from the translation initiator Met (positions −11 and −10 with respect to the beginning of the mature enzyme), and processed to mature extracellular enzymes in which the NH2-terminal amino acid sequences were the same as that of the parental pTUB607 α-amylase, in spite of the lengths of the prosequences and the amino acid composition near the secondary cleavage sites being different in each enzyme.", }