We study the role of the dimer structure of light-harvesting complex II (LH2) in excitation transfer from the LH2 [without a reaction center (RC)] to the LH1 (surrounding the RC) or from the LH2 to another LH2. The excited and unexcited states of a bacteriochlorophyll (BChl) are modeled by a quasispin. In the framework of quantum open system theory, we represent the excitation transfer as the t...

A cyclodextrin dimer has been synthesized with two beta-cyclodextrins linked by a flexible chain containing a carbon-carbon double bond. This dimer binds and solubilizes a phthalocyanine-based photosensitizer that generates singlet oxygen on irradiation. When the complex is irradiated, the singlet oxygen cleaves the carbon-carbon link, and the cyclodextrins are released, liberating the photosen...

We have demonstrated that the bldB gene of Streptomyces coelicolor is required for the formation of aerial hyphae and the synthesis of antibiotics. We also found that BldB forms a higher-order complex (most likely a dimer) and that amino acid residues 20 to 78 are important for this interaction. This region is conserved in the BldB family, suggesting that dimer formation may be a common feature...

AMPA- and kainate (KA)-selective ionotropic glutamate receptors (iGluRs) respond to agonist by opening (gating), then closing (desensitizing) in quick succession. Gating has been linked to agonist-induced changes within the ligand-binding domain (LBD), and desensitization to rearrangement of a dimer formed by neighboring LBDs. To explore the role of dimer conformation in both gating and desensi...

Obstructive sleep apnoea is a risk factor for pulmonary embolism. Elevated D-dimer levels and other biomarkers are associated with recurrent pulmonary embolism. The objectives were to compare the frequency of elevated D-dimer levels (>500 ng·mL(-1)) and further coagulation biomarkers after oral anticoagulation withdrawal in pulmonary embolism patients, with and without obstructive sleep apnoea,...

CD4 is a coreceptor for binding of T cells to APC and the primary receptor for HIV. The disulfide bond in the second extracellular domain (D2) of CD4 is reduced on the cell surface, which leads to formation of disulfide-linked homodimers. A large conformational change must take place in D2 to allow for formation of the disulfide-linked dimer. Domain swapping of D2 is the most likely candidate f...

The conserved DPY-30 is an essential component of the dosage compensation complex that balances the X-linked gene expression by regulation of the complex formation in Caenorhabditis elegans. The human DPY-30-like protein (DPY-30L) homolog is a conserved member of certain histone methyltransferase (HMT) complexes. In the human MLL1 (mixed-lineage leukemia-1) HMT complex, DPY-30L binds to the BRE...

heterodimers and possibly higher-order oligomers, following activation by a subset of a dozen potential li-gands including EGF, transforming growth factor ␣ The human EGFR is a large (1186 residues), mono-Parkville, Victoria 3050 Australia meric, modular glycoprotein with an extracellular ligand binding domain, a transmembrane region, and an intra-4 CSIRO Health Sciences and Nutrition 343 Royal...

A large protein machinery is required for 3'-end processing of mRNA precursors in eukaryotes. Cleavage factor IA (CF IA), a complex in the 3'-end processing machinery in yeast, contains four subunits, Rna14, Rna15, Clp1, and Pcf11. Rna14 has a HAT (half a TPR) domain at the N terminus and a region at the C terminus that mediates interactions with Rna15. Rna15 contains a RNA recognition module (...

The hPrp19/CDC5L complex is a non-snRNP spliceosome complex that plays a key role in the spliceosome activation during pre-mRNA splicing, and CTNNBL1 and CDC5L are essential components of the complex. In this study, to investigate the oligomeric state of CTNNBL1 in solution, we performed small angle X-ray scattering experiments in various concentrations of NaCl. We observed that CTNNBL1 existed...