Despite emergence of bis-ANS as a major fluorescence probe of proteins structure, conformational and spectroscopic properties of protein/bis-ANS complexes remains largely unexplored. We have shown that fluorescence polarization of both ANS and bis-ANS is excitation wavelength dependent and this is a property of all protein-ANS/bis-ANS complexes studied. Bis-ANS excitation maximum is always more red shifted than the corresponding ANS complex. Even when corrected for the red shift, the bis-ANS complexes in some, but not all, cases show only a little lowering of polarization, suggesting modest additional depolarization in bis-ANS compared to ANS. Calculation of energy migration rate between the two rings suggests that energy migration rate should be high at all values of the naphthyl-naphthyl dihedral angle. Although, Molecular mechanics and dynamics calculations show that the lowest energy conformation of bis-ANS is when the two naphthalene rings are roughly perpendicular to each other, due to rapid energy migration this conformation should lead to dramatic lowering of emission anisotropy, unlike what is observed. Salt and temperature dependence of bis-ANS/protein interaction suggests little ionic interaction and pre-dominant interaction through hydrophobic aromatic rings. We conclude that bis-ANS binds to proteins through interaction with the aromatic rings and with two rings nearly parallel to each other.

Frankia are nitrogen-fixing actinomycetes that form a symbiotic association with over 200 species of woody dicotyledonous plants. Recently, three Frankia genomes were completely sequenced. In this study, the synonymous codon usage patterns of three Frankia genomes (strains CcI3, ACN14a, and EAN1pec) were determined and compared to each other and to other actinobacteria. As expected for a high G+C organism, codon usage by Frankia was highly biased, but differences were observed among the three strains. Using the codon adaptation index (CAI) as a numerical estimator of gene expression level, highly expressed genes in Frankia were predicted with ribosomal protein genes as a reference. The analysis of the predicted highly expressed genes showed that Frankia strain CcI3 had a different profile from the other two strains. Strain CcI3 had fewer predicted highly expressed genes in several COG categories including lipid transport and metabolism, secondary metabolites biosynthesis, inorganic ion transport and metabolism, and general function prediction only than Frankia strains EAN1pec and ACN14a. Interestingly, Frankia EAN1pec had more predicted highly expressed genes in transcription and signal transduction mechanisms than the other two strains. These differences were not just a reflection in total gene numbers, but also based on percentage of genes within a category. These results support the hypothesis that strain CcI3 is becoming a symbiotic specialist and the other two facultative symbiotic strains are maintaining their capacity to exist as free-living soil dwellers.

Bamboo, the “Green Gold”, included in the non-timber forest products has both ecological and economic importance. Here is an attempt to describe a database named “Bambooinfoline” , which provides enumeration of the different species of bamboos found in North Bengal, with special emphasis on taxonomy, edible properties, chemical constituents, morphological features along with tissue culture specifications, which in turn benefits of scientific community.AvailabilityThe database is freely available at http://www.bamboodb.ind.in/

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A comprehensive in silico analysis of 71 species representing the different taxonomic classes and physiological genre of the domain Archaea was performed. These organisms differed in their physiological attributes, particularly oxygen tolerance and energy metabolism. We explored the diversity and similarity in the codon usage pattern in the genes and genomes of these organisms, emphasizing on their core cellular pathways. Our thrust was to figure out whether there is any underlying similarity in the design of core pathways within these organisms. Analyses of codon utilization pattern, construction of hierarchical linear models of codon usage, expression pattern and codon pair preference pointed to the fact that, in the archaea there is a trend towards biased use of synonymous codons in the core cellular pathways and the Nc-plots appeared to display the physiological variations present within the different species. Our analyses revealed that aerobic species of archaea possessed a larger degree of freedom in regulating expression levels than could be accounted for by codon usage bias alone. This feature might be a consequence of their enhanced metabolic activities as a result of their adaptation to the relatively O2-rich environment. Species of archaea, which are related from the taxonomical viewpoint, were found to have striking similarities in their ORF structuring pattern. In the anaerobic species of archaea, codon bias was found to be a major determinant of gene expression. We have also detected a significant difference in the codon pair usage pattern between the whole genome and the genes related to vital cellular pathways, and it was not only species-specific but pathway specific too. This hints towards the structuring of ORFs with better decoding accuracy during translation. Finally, a codon-pathway interaction in shaping the codon design of pathways was observed where the transcription pathway exhibited a significantly different coding frequency signature.