Hiroshi Tsujibo

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Streptomyces thermoviolaceus OPC-520 secretes two types of xylanases (StxI and StxII), an acetyl xylan esterase (StxIII), and an alpha-L-arabinofuranosidase (StxIV) in the presence of xylan. Xylan degradation products (mainly xylobiose) produced by the action of these enzymes entered the cell and were then degraded to xylose by an intracellular(More)
An extracellular alkaline metalloprotease (MprI) from Alteromonas sp. strain O-7 was purified and characterized. The molecular mass of the purified enzyme was estimated to be 56 kDa by SDS-PAGE. The optimum pH and temperature were pH 10.0 and 60 degrees C, respectively. The gene (mprI) encoding MprI was cloned and its nucleotide sequence was analyzed. The(More)
The ferric uptake regulator (Fur) box-like sequence was located upstream of the serine protease-encoding gene (aprII) from a marine bacterium, Alteromonas sp. strain O-7. To clarify whether the production of AprII (the gene product of aprII) is regulated by the environmental iron concentrations, this strain was cultured under iron-depleted or iron-rich(More)
A pvsB-vctA-irgA triple deletion mutant of Vibrio parahaemolyticus can utilize enterobactin under iron-limiting conditions by inducing a previously undescribed receptor, PeuA (VPA0150), in response to extracellular alkaline pH and enterobactin. In silico analyses revealed the existence of a two-component regulatory system operon, peuRS, immediately upstream(More)
Vibrio vulnificus, an opportunistic pathogen that causes a serious, often fatal, infection in humans, requires iron for its growth. This bacterium utilizes iron from the environment via the vulnibactin-mediated iron uptake system. The mechanisms of vulnibactin biosynthesis, vulnibactin export, and ferric-vulnibactin uptake systems have been reported,(More)
Alteromonas sp. strain O-7 secretes several proteins in addition to chitinolytic enzymes in response to chitin induction. In this paper, we report that one of these proteins, designated MprIII, is a metalloprotease involved in the chitin degradation system of the strain. The gene encoding MprIII was cloned in Escherichia coli. The open reading frame of(More)
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