Ownership structure, investment behaviour and firm performance in Japanese manufacturing industries

Abstract Using data spanning the 1996-98 fiscal years of 247 of Japan's largest manufacturers, we empirically evaluate the extent to which a firm's investment behaviour and financial performance are influenced by its ownership structure. To do so, we examine six distinct categories of Japanese shareholders: foreign investors, investment funds, pension funds, banks and insurance companies, affiliated companies and insiders. Our findings strongly indicate that the relationship between the equity stakes of a particular category of investor and a firm's financial performance and investment behaviour is considerably more complex than is depicted in simple principal-agent representations. Such a result emphasizes the importance of making finely grained and contextually relevant distinctions when modelling and evaluating corporate governance relations

Enhancement of thioredoxin/glutaredoxin-mediated L-cysteine synthesis from <it>S</it>-sulfocysteine increases L-cysteine production in <it>Escherichia coli</it>

<p>Abstract</p> <p>Background</p> <p><it>Escherichia coli</it> has two L-cysteine biosynthetic pathways; one is synthesized from <it>O</it>-acetyl L-serine (OAS) and sulfate by L-cysteine synthase (CysK), and another is produced via <it>S</it>-sulfocysteine (SSC) from OAS and thiosulfate by SSC synthase (CysM). SSC is converted into L-cysteine and sulfite by an uncharacterized reaction. As thioredoxins (Trx1 and Trx2) and glutaredoxins (Grx1, Grx2, Grx3, Grx4, and NrdH) are known as reductases of peptidyl disulfides, overexpression of such reductases might be a good way for improving L-cysteine production to accelerate the reduction of SSC in <it>E. coli</it>.</p> <p>Results</p> <p>Because the redox enzymes can reduce the disulfide that forms on proteins, we first tested whether these enzymes catalyze the reduction of SSC to L-cysteine. All His-tagged recombinant enzymes, except for Grx4, efficiently convert SSC into L-cysteine <it>in vitro</it>. Overexpression of Grx1 and NrdH enhanced a 15-40% increase in the <it>E. coli</it>L-cysteine production. On the other hand, disruption of the <it>cysM</it> gene cancelled the effect caused by the overexpression of Grx1 and NrdH, suggesting that its improvement was due to the efficient reduction of SSC under the fermentative conditions. Moreover, L-cysteine production in knockout mutants of the sulfite reductase genes (Δ<it>cysI</it> and Δ<it>cysJ</it>) and the L-cysteine synthase gene (Δ<it>cysK</it>) each decreased to about 50% of that in the wild-type strain. Interestingly, there was no significant difference in L-cysteine production between wild-type strain and gene deletion mutant of the upstream pathway of sulfite (Δ<it>cysC</it> or Δ<it>cysH</it>). These results indicate that sulfite generated from the SSC reduction is available as the sulfur source to produce additional L-cysteine molecule. It was finally found that in the <it>E. coli</it>L-cysteine producer that co-overexpress glutaredoxin (NrdH), sulfite reductase (CysI), and L-cysteine synthase (CysK), there was the highest amount of L-cysteine produced per cell.</p> <p>Conclusions</p> <p>In this work, we showed that Grx1 and NrdH reduce SSC to L-cysteine, and the generated sulfite is then utilized as the sulfur source to produce additional L-cysteine molecule through the sulfate pathway in <it>E. coli</it>. We also found that co-overexpression of NrdH, CysI, and CysK increases L-cysteine production. Our results propose that the enhancement of thioredoxin/glutaredoxin-mediated L-cysteine synthesis from SSC is a novel method for improvement of L-cysteine production.</p