PENGARUH DEWAN KOMISARIS ASING, DEWAN KOMISARIS INDEPENDEN DAN KEPEMILIKAN SAHAM ASING TERHADAP NILAI PERUSAHAAN (STUDI EMPIRIS PADA PERUSAHAAN MANUFAKTUR YANG TERDAFTAR DI BEI TAHUN 2009-2011)

Penelitian ini bertujuan untuk menguji pengaruh dewan komisaris asing, dewan komisaris independen dan kepemilikan saham asing terhadap nilai perusahaan manufaktur yang terdaftar di BEI (Bursa Efek Indonesia) selama periode pengamatan (2009-2011).Penelitian ini merupakan penelitian empiris dengan pendekatan kuantitatif yang melibatkan penggunaan analisa statistik. Penelitian ini menggunakan data sekunder. Alat analisisnyang digunakan dalam penelitian ini adalah regresi linier berganda dengan bantuan sofware SPSS (Statistical Package for Social Scienc) Hasil penelitian menunjukkan bahwa dewan komisaris asing dan kepemilikan saham asing berpengaruh positif dan signifikan terhadap nilai perusahaan, sedangkan variabel dewan komisaris independen tidak mempunyai pengaruh yang signifikan terhadap nilai perusahaan

The Escherichia coli CysZ is a pH dependent sulfate transporter that can be inhibited by sulfite

The Escherichia coli inner membrane protein CysZ mediates the sulfate uptake subsequently utilized for the synthesis of sulfur-containing compounds in cells. Here we report the purification and functional characterization of CysZ. Using Isothermal Titration Calorimetry, we have observed interactions between CysZ and its putative substrate sulfate. Additional sulfur-containing compounds from the cysteine synthesis pathway have also been analyzed for their abilities to interact with CysZ. Our results suggest that CysZ is dedicated to a specific pathway that assimilates sulfate for the synthesis of cysteine. Sulfate uptake via CysZ into E. coli whole cells and proteoliposome offers direct evidence of CysZ being able to mediate sulfate uptake. In addition, the cysteine synthesis pathway intermediate sulfite can interact directly with CysZ with higher affinity than sulfate. The sulfate transport activity is inhibited in the presence of sulfite, suggesting the existence of a feedback inhibition mechanism in which sulfite regulates sulfate uptake by CysZ. Sulfate uptake assays performed at different extracellular pH and in the presence of a proton uncoupler indicate that this uptake is driven by the proton gradient

Molecular and Biochemical Analysis of Chalcone Synthase from Freesia hybrid in Flavonoid Biosynthetic Pathway

Chalcone synthase (CHS) catalyzes the first committed step in the flavonoid biosynthetic pathway. In this study, the cDNA (FhCHS1) encoding CHS from Freesia hybrida was successfully isolated and analyzed. Multiple sequence alignments showed that both the conserved CHS active site residues and CHS signature sequence were found in the deduced amino acid sequence of FhCHS1. Meanwhile, crystallographic analysis revealed that protein structure of FhCHS1 is highly similar to that of alfalfa CHS2, and the biochemical analysis results indicated that it has an enzymatic role in naringenin biosynthesis. Moreover, quantitative real-time PCR was performed to detect the transcript levels of FhCHS1 in flowers and different tissues, and patterns of FhCHS1 expression in flowers showed significant correlation to the accumulation patterns of anthocyanin during flower development. To further characterize the functionality of FhCHS1, its ectopic expression in Arabidopsis thaliana tt4 mutants and Petunia hybrida was performed. The results showed that overexpression of FhCHS1 in tt4 mutants fully restored the pigmentation phenotype of the seed coats, cotyledons and hypocotyls, while transgenic petunia expressing FhCHS1 showed flower color alteration from white to pink. In summary, these results suggest that FhCHS1 plays an essential role in the biosynthesis of flavonoid in Freesia hybrida and may be used to modify the components of flavonoids in other plants

Salt-bridge dynamics control substrate-induced conformational change in the membrane transporter GlpT.

Active transport of substrates across cytoplasmic membranes is of great physiological, medical and pharmaceutical importance. The glycerol-3-phosphate (G3P) transporter (GlpT) of the E. coli inner membrane is a secondary active antiporter from the ubiquitous major facilitator superfamily that couples the import of G3P to the efflux of inorganic phosphate (Pi) down its concentration gradient. Integrating information from a novel combination of structural, molecular dynamics simulations and biochemical studies, we identify the residues involved directly in binding of substrate to the inward-facing conformation of GlpT, thus defining the structural basis for the substrate-specificity of this transporter. The substrate binding mechanism involves protonation of a histidine residue at the binding site. Furthermore, our data suggest that the formation and breaking of inter- and intradomain salt bridges control the conformational change of the transporter that accompanies substrate translocation across the membrane. The mechanism we propose may be a paradigm for organophosphate:phosphate antiporters

Sequence and crystal structural analysis of FhCHS1.

<p>A, Comparison of amino acid sequences between FhCHS1, AtCHS (At5913930), PhCHSA (X14591) and MsCHS2 (L02902). Functionally important conserved residues are highlighted with a colored background: pink, the three conserved catalytic residues in all CHS; blue, two important residues determining the substrate specificity of CHS; yellow, the malonyl-CoA binding motif; red, highly conserved CHS signature sequence. B, Functional unit of CHS. The homo-dimer with one of the monomer highlighting secondary structure components: cyan for α-helix, magenta for β-strand, pink for loop. C, Structure comparison of the current CHS of freesia (blue, PDB ID 4WUM) and previous structure model CHS2 of alfalfa (yellow, PDB ID 1BI5), indicating strong structural conservation of the CHS protein.</p

Phylogenetic tree based on the amino acid sequences of plant CHSs.

<p>The tree was constructed using the MEGA 5.1 and neighbor-joining method with 2000 bootstrap replicates. <i>Freesia hybrida</i> CHS is boxed. GenBank accession numbers used are: <i>Nelumbo nucifera</i> (<i>Nn</i>CHS, FJ999628.1), <i>Abelmoschus manihot</i> (<i>Am</i>CHS, EU573212.1), <i>Nicotiana tabacum</i> (<i>Nt</i>CHS, AF311783.1), <i>petunia hybrida</i> (<i>Ph</i>CHSA, X14591; <i>Ph</i>CHSB, X14592; <i>Ph</i>CHSD, X14593; <i>Ph</i>CHSF, X14594; <i>Ph</i>CHSG, X14595; <i>Ph</i>CHSJ, X14597), <i>Saussurea medusa</i> (<i>Sm</i>CHS, DQ350888.1), <i>Humulus lupulus</i> (<i>Hl</i>CHS, CAK19317.1), <i>Anthurium andraeanum</i> (<i>Aa</i>CHS, DQ421809.1), <i>Freesia hybrida</i> (<i>Fh</i>CHS1, JF732897.1), <i>Iris germanica</i> (<i>Ig</i>CHS, AB219147.1), <i>Camellia chekiangoleosa</i> (<i>Cc</i>CHS1, JN944573.1; <i>Cc</i>CHS2, JN944574.1), <i>Rosa chinensis</i> (<i>Rc</i>CHS, HQ423171.1), <i>Melastoma malabathricum</i> (<i>Mm</i>CHS, KF234569.1), <i>Rhododendron simsii</i> (<i>Rs</i>CHS, AJ413277.1), <i>Camellia nitidissima</i> (<i>Cn</i>CHS, HQ269804.1).</p

Schematic diagram of the generalized structure of <i>FhCHS1</i> gene.

<p>A, Exons-intron architecture of <i>FhCHS1</i>. exons, intron, initiation codon (ATG) and terminator codon (TAA) are labeled. B, Nucleotide sequences surrounding splice sites in <i>FhCHS1</i>, <i>AmCHS</i> (<i>Antirrhinum majus CHS</i>, X03710) and <i>PpCHS11</i> (<i>Physcomitrella patens CHS</i>, ABU87504). Amino acid residues and codons (underlined) split by introns are shown.</p

Functional characterization of <i>FhCHS1</i> gene following its overexpression in transgenic petunia lines.

<p>A, Differences in color between wild-type and transgenic petunia flowers. B, Expressional analysis of the <i>FhCHS1</i> gene by reverse transcription polymerase chain reaction in the wild-type and transgenic lines. C, Extracted solutions from flowers of wild-type and transgenic lines. D, Contents of anthocyanidins and flavonols in the wild-type and transgenic petunia flowers. Data correspond to means of three biological replicates. Means with different letters within the same column are significantly different at the 0.01 level of probability. N/D, not detected.</p

<i>FhCHS1</i> gene expression profiles in <i>Freesia hybrida</i>.

<p>A, The phenotypes of different samples. 1–5, represent the flowers of different developmental stages; Pe, petals; St, stamens; Pi, pistils; Ca, calyxes; To, toruses; Sc, scapes; Le, leaves; Ro, roots. B, Expression profile of <i>FhCHS</i>1 in flowers at different developmental stages. C, Expression levels of <i>FhCHS</i>1 in different tissues. Data represent means ± SD of three biological replicates.</p

Enzyme activity of freesia (<i>Freesia hybrida</i>) chalcone synthase (FhCHS1).

<p>A, The sample of naringenin standard. B, The reaction products catalyzed by FhCHS1. C, Control.</p