Publications by authors named "Tomonori Akiyama"

Microbacterium hydrocarbonoxydans has been isolated using an unnatural acylhydrazide compound as the sole carbon source. The compound is hydrolyzed by bacterial hydrazidase, and the gene expression of the enzyme is considered to be controlled by a transcription factor of the Isocitrate lyase Regulator (IclR) family, belonging to the one-component signaling systems. Recently, we reported the crystal structure of an unliganded IclR homolog from M.

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Microbacterium hydrocarbonoxydans was isolated, using hydrazide compounds as its sole carbon source. The key enzyme that metabolizes these compounds was identified as hydrazidase, and the operon containing the gene coding for the enzyme, was revealed by genome sequencing. The operon also contained genes coding for an ATP-binding cassette transporter (ABC transporter), which was expected to transport the hydrazide compounds.

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In Arabidopsis, signaling of the stress hormone abscisic acid (ABA) is mediated by PYR/PYL/RCAR receptors (PYLs), which bind to and inhibit group-A protein phosphatases 2C (PP2Cs), the negative regulators of ABA. X-ray structures of several PYL-ABA and PYL-ABA-PP2C complexes have revealed that a conserved tryptophan in PP2Cs is inserted into a small tunnel adjacent to the C4' of ABA in the PYL-ABA complex and plays a crucial role in the formation and stabilization of the PYL-ABA-PP2C complex. Here, 4'-modified ABA analogues were designed to prevent the insertion of the tryptophan into the tunnel adjacent to the C4' of ABA in these complexes.

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The bacterial transcription factor IclR (isocitrate lyase regulator) is a member of a one-component signal transduction system, which shares the common motif of a helix-turn-helix (HTH)-type DNA-binding domain (DBD) connected to a substrate-binding domain (SBD). Here, the crystal structure of an IclR homologue (Mi-IclR) from Microbacterium sp. strain HM58-2, which catabolizes acylhydrazide as the sole carbon source, is reported.

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Hydrazidase was an enzyme that remained unidentified for a half century. However, recently, it was purified, and its encoding gene was cloned. Microbacterium sp.

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We report the draft genome sequence of Microbacterium sp. strain HM58-2, which produces hydrazidase, an enzyme hydrolyzing acylhydrazides. The estimated genome size is 3.

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Clostridium botulinum produces a large toxin complex (L-TC) comprising botulinum neurotoxin associated with auxiliary nontoxic proteins. A complex of 33- and 17-kDa hemagglutinins (an HA-33/HA-17 trimer) enhances L-TC transport across the intestinal epithelial cell layer via binding HA-33 to a sugar on the cell surface. At least two subtypes of serotype C/D HA-33 exhibit differing preferences for the sugars sialic acid and galactose.

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The plant stress hormone abscisic acid (ABA) is critical for several abiotic stress responses. ABA signaling is normally repressed by group-A protein phosphatases 2C (PP2Cs), but stress-induced ABA binds Arabidopsis PYR/PYL/RCAR (PYL) receptors, which then bind and inhibit PP2Cs. X-ray structures of several receptor-ABA complexes revealed a tunnel above ABA's 3' ring CH that opens at the PP2C binding interface.

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The botulinum toxin complex, the causative agent of botulism, passes through the intestinal wall via sugar-chain-dependent cell binding of a haemagglutinin of 33 kDa molecular weight (HA-33). The amino-acid sequence of the C-terminal half of HA-33 of the serotype C strain Yoichi (C-Yoichi) shares only 46% identity with those of the major serotype C strains. Additionally, C-Yoichi HA-33 exhibits a unique sugar-binding specificity.

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Vialinin A, a small compound isolated from the Chinese mushroom Thelephora vialis, exhibits more effective anti-inflammatory activity than the widely used immunosuppressive drug tacrolimus (FK506). Here, we show that ubiquitin-specific peptidase 5/isopeptidase T (USP5/IsoT) is a target molecule of vialinin A, identified by using a beads-probe method. Vialinin A inhibited the peptidase activity of USP5/IsoT and also inhibited the enzymatic activities of USP4 among deubiquitinating enzymes tested.

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Objective: The objective of this study was to develop a novel polymerase chain reaction (PCR) method to comprehensively analyze salivary bacterial flora.

Study Design: The bacterial flora in the saliva of 10 healthy persons and 11 patients with odontogenic infections were examined using a DNA extraction method with a high level of cell destruction efficiency and a novel universal primer set to amplify approximately 580 bp of the 16S rDNA sequence.

Results: Streptococcus (54.

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Moraxella catarrhalis, formerly called Branhamella catarrhalis, 'Neisseria catarrhalis' or 'Micrococcus catarrhalis', is a Gram-negative, aerobic diplococcus frequently found as a colonizer of the upper respiratory tract. Over the last 20-30 years, this bacterium has emerged as a genuine pathogen, and is now considered an important cause of otitis media in children and an aetiological agent in pneumonia in adults with chronic obstructive pulmonary disease. However, bacteraemia due to M.

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