In silico Protein Structural Modeling and Active binding site Evaluation of Streptococcus pneumoniae

Structure function relation of glucose kinese in Streptococcus pneumoniae. However, a solved structure for _Streptococcus pneumoniae_ glucose kinese is not available at the protein data bank. Glucose kinase is a regulatory enzyme capable of adding phosphate group to glucose in the first step of streptomycin biosynthesis. The activity of glucose kinase was regulated by the Carbon Catabolite Repression system. So, we created a model of glucose kinese from _Streptococcus pnemoniae_ using the X-ray crystallography structure of glucose kinese enzymes from _Enterobacteria faecalis_ as template with Molsoft ICM v3.5 software. The model was validated using protein structure checking tools such as PROCHECK, WHAT IF: for reliability. The active site amino acid "Asp114" in the template is retained in _S. pneumoniae_ Glucose kinese model "Asp115". Solvent accessible surface area analysis of the glucose kinese model showed that known key residues playing important role in active site for ligand binding and metal ion binding are buried and hence not accessible to solvent. The information thus discussed provides insight to the molecular understanding of _Streptococcus pneumoniae_ in glucose kinase

Curvature Inspired Cosmological Scenario

Using modified gravity with non-linear terms of curvature, $R^2$ and $R^{(r +2)}$ (with $r$ being the positive real number and $R$ being the scalar curvature), cosmological scenario,beginning at the Planck scale, is obtained. Here, a unified picture of cosmology is obtained from $f(R)-$ gravity. In this scenario, universe begins with power-law inflation, followed by deceleration and acceleration in the late universe as well as possible collapse of the universe in future. It is different from $f(R)-$ dark energy models with non-linear curvature terms assumed as dark energy. Here, dark energy terms are induced by linear as well as non-linear terms of curvature in Friedmann equation being derived from modified gravity.It is also interesting to see that, in this model, dark radiation and dark matter terms emerge spontaneously from the gravitational sector. It is found that dark energy, obtained here, behaves as quintessence in the early universe and phantom in the late universe. Moreover, analogous to brane-tension in brane-gravity inspired Friedmann equation, a tension term $\lambda$ arises here being called as cosmic tension. It is found that, in the late universe, Friedmann equation (obtained here) contains a term $- \rho^2/2\lambda$ ($\rho$ being the phantom energy density) analogous to a similar term in Friedmann equation with loop quantum effects, if $\lambda > 0$ and brane-gravity correction when $\lambda < 0.$Comment: 19 Pages. To appear in Int. J. Thro. Phy