Local QSAR based on quantum chemistry calculations for the stability of nitrenium ions to reduce false positive outcomes from standard QSAR systems for the mutagenicity of primary aromatic amines.

Background: Primary aromatic amines (PAAs) present significant challenges in the prediction of mutagenicity using current standard quantitative structure activity relationship (QSAR) systems, which are knowledge-based and statistics-based, because of their low positive prediction values (PPVs). Previous studies have suggested that PAAs are metabolized into genotoxic nitrenium ions. Moreover, ddE, a relative-energy based index derived from quantum chemistry calculations that measures the stability nitrenium ions, has been correlated with mutagenicity.

Rice gene is expressed in mitotic cells and regulates pleiotropic features during vegetative phase.

Cell division is important for organisms to grow and repair damaged tissues. A mutant screen in rice has identified dwarf () mutants that code for a novel protein potentially involved in mitosis including cytokinesis in rice. The gene is expressed during the mitotic phase and a defect in the gene induces cells with two nuclei.

Mechanism of tRNA recognition by heterotetrameric glycyl-tRNA synthetase from lactic acid bacteria.

Glycyl-tRNA synthetases (GlyRSs) have different oligomeric structures depending on the organisms. While a dimeric α2 GlyRS species is present in archaea, eukaryotes and some eubacteria, a heterotetrameric α2β2 GlyRS species is found in most eubacteria. Here, we present the crystal structure of heterotetrameric α2β2 GlyRS, consisting of the full-length α and β subunits, from Lactobacillus plantarum (LpGlyRS), gram-positive lactic bacteria.

Intron-Dependent or Independent Pseudouridylation of Precursor tRNA Containing Atypical Introns in .

Eukaryotic precursor tRNAs (pre-tRNAs) often have an intron between positions 37 and 38 of the anticodon loop. However, atypical introns are found in some eukaryotes and archaea. In an early-diverged red alga , the tRNA(UAU) gene contains three intron coding regions, located in the D-, anticodon, and T-arms.

Specification of basal region identity after asymmetric zygotic division requires mitogen-activated protein kinase 6 in rice.

Asymmetric cell division is a key step in cellular differentiation in multicellular organisms. In plants, asymmetric zygotic division produces the apical and basal cells. The mitogen-activated protein kinase (MPK) cascade in acts in asymmetric divisions such as zygotic division and stomatal development, but whether the effect on cellular differentiation of this cascade is direct or indirect following asymmetric division is not clear.