リプライ3 (「労使関係の転換と選択--日本の自動車産業」戸塚秀夫,兵藤編著)

textapplication/pdfdepartmental bulletin pape

Genes essential for the morphogenesis of the Shiga toxin 2-transducing phage from Escherichia coli O157:H7

Shiga toxin 2 (Stx2), one of the most important virulence factors of enterohaemorrhagic Escherichia coli (EHEC), is encoded by phages. These phages (Stx2 phages) are often called lambda-like. However, most Stx2 phages are short-tailed, thus belonging to the family Podoviridae, and the functions of many genes, especially those in the late region, are unknown. In this study, we performed a systematic genetic and morphological analysis of genes with unknown functions in Sp5, the Stx2 phage from EHEC O157:H7 strain Sakai. We identified nine essential genes, which, together with the terminase genes, determine Sp5 morphogenesis. Four of these genes most likely encoded portal, major capsid, scaffolding and tail fiber proteins. Although exact roles/functions of the other five genes are unknown, one was involved in head formation and four were required for tail formation. One of the four tail genes encoded an unusually large protein of 2,793 amino-acid residues. Two genes that are likely required to maintain the lysogenic state were also identified. Because the late regions of Stx2 phages from various origins are highly conserved, the present study provides an important basis for better understanding the biology of this unique and medically important group of bacteriophages.Citation: Mondal SI, Islam MR, Sawaguchi A, Asadulghani M, Ooka T, Gotoh Y, Kasahara Y, Ogura Y, Hayashi T. Genes essential for the morphogenesis of the Shiga toxin 2-transducing phage from Escherichia coli O157:H7. Sci Rep. 2016 Dec 14;6:39036. doi: 10.1038/srep39036. PMID: 27966628; PMCID: PMC5155283

Observation of a Resonancelike Structure in the π^+-Ψ' Mass Distribution in Exclusive B → Kπ^+-Ψ' Decays

A distinct peak is observed in the π^±Ψ'invariant mass distribution near 4.43 GeV in B→ Kπ^±Ψ' decays. A fit using a Breit-Wigner resonance shape yields a peak mass and width of M = 4433± 4(stat)± 2(syst) MeV and Γ= 45\begin+18\-13\end(stat)\begin+30\-13\end(syst)MeV.The product branching fraction is determined to be B(B^0→ K^∓Z^±(4430)→ π^±Ψ')= (4.1±1.0(stat)±1.4(syst))×10^{-5}, where Z^±(4430)is used to denote the observed structure. The statistical significance of the observed peak is 6.5σ. These results are obtained from a 605 fb^{-1} data sample that contains 657 ×10^6 B\bar{B} pairs collected near the Υ(4S) resonance with the Belle detector at the KEKB asymmetric energy e^+e^- collider.journal articl

Evidence for Direct CP Violation in B0→K+π-Decays

journal articl

Normal Modes of Prion Proteins: From Native to Infectious Particle

Prion proteins (PrP) are the infectious agent in transmissible spongiform encephalopathies (i.e., mad cow disease). To be infectious, prion proteins must undergo a conformational change involving a decrease in α-helical content along with an increase in β-strand content. This conformational change was evaluated by means of elastic normal modes. Elastic normal modes show a diminution of two α-helices by one and two residues, as well as an extension of two β-strands by three residues each, which could instigate the conformational change. The conformational change occurs in a region that is compatible with immunological studies, and it is observed more frequently in mutant prions that are prone to conversion than in wild-type prions because of differences in their starting structures, which are amplified through normal modes. These findings are valuable for our comprehension of the conversion mechanism associated with the conformational change in prion proteins

Preface

othe

Brownian Motion on the Surface of a Spherical Cell as Given by Equation 1

<div><p>Figure 1 verifies that the SDE constructed in <a href="http://www.ploscompbiol.org/article/info:doi/10.1371/journal.pcbi.0020044#pcbi-0020044-e001" target="_blank">Equation 1</a> correctly describes the random diffusive movement of membrane bound particles. Shown are trajectories of a diffusing particle on the surface of a cell with 10 <i>μm</i> radius for a fixed time with different diffusion coefficients.</p><p>(A) <i>D</i> = 0<i>.</i>03 <i>μm</i>²/<i>s,</i> (B) <i>D</i> = 0<i>.</i>3 <i>μm</i>²/<i>s,</i> (C) <i>D</i> = 3 <i>μm</i>²/<i>s</i>.</p></div

Illustration of the Model for the Receptor Dimerization Process

<p>As soon as receptors are introduced onto the cell surface, they undergo isotropic Brownian motion. At any given time, there is a small constant probability that a protein may be removed from the cell surface via endocytosis. If at any time two receptors of different type come within close proximity, they may form an active dimeric complex with probability <i>p</i>.</p