Role of Linkers between Zinc Fingers in Spacing Recognition by Plant TFIIIA-Type Zinc-Finger Proteins

The EPF family of plant TFIIIA-type zinc-finger (ZF) proteins (ZPTs) is characterized by long linkers separating ZF motifs. We previously reported that two-fingered ZPTs bind to two tandem core sites that are separated by several base pairs, each ZF making contact with one core site. Here we report further characterization of DNA-binding activities of ZPTs using four family members, ZPT2-14, ZPT2-7, ZPT2-8, and ZPT2-2, having inter-ZF linkers of different lengths and sequences, to investigate the correlation of the length and/or sequence of the linker with preference for the spacing between core sites in target DNAs. Selected and amplified binding site (SAAB)-imprinting assays and gel mobility shift assays prompted three conclusions. (1) The four ZPTs have common specificity for core binding sites—two AGT(G)/(C)ACTs separated by several nucleotides. (2) The four ZPTs prefer a spacing of 10 bases between the core sites, but each ZPT has its own preference for suboptimal spacing. (3) At a particular spacing, two zinc fingers may bind to the core sites on both strands. The results provide new information about how the diversity in linker length/sequence affects DNA-sequence recognition in this protein family

Angular distribution control of extreme ultraviolet radiation from laser-produced plasma by manipulating the nanostructure of low-density SnO 2 targets

金沢大学先端科学・社会共創推進機構We have found that the divergence of a relatively monochromatic extreme ultraviolet (EUV) emission from a laser-produced plasma can be manipulated by changing the target morphology which is a porous low-density tin oxide (Sn O2) structure. The fundamental light of a Nd-YAG laser was irradiated on the target with laser intensity of ∼ 1011 W cm2 and pulse duration of 10 ns. The nanostructure and density of the targets were tuned by a combination of colloidal polymer template and sol-gel processes [Gu, Nagai, Norimatsu, Fujioka, Nishimura, Nishihara, Miyanaga, and Izawa, Chem. Mater. 17, 1115 (2005)], which has a merit in large-scale preparation. When the target has an open cell nanostructure, the EUV emission directed predominantly along target normal, while a closed cell target exhibited divergent emission. The angular distribution may be affected by the orientation of the microstructured initial target, and this phenomenon can be applied to wavefront control of EUV emission. © 2006 American Institute of Physics.Embargo Period 12 month