System analysis of salt and osmotic stress induced proteins in Nostoc muscorum and Bradyrhizobium japonicum

In this study the proteome response of the two diazotrophic organism's viz. Nostoc muscorum and Bradyrhizobium japonicum exposed to salt (NaCl) and osmotic (sucrose) stresses was compared. Out of the total over expressed proteins; we have selected only three over expressed proteins viz. GroEL chaperonin, nitrogenase Mo-Fe protein and argininosuccinate synthase for further analysis, and then we analyzed the amino acid frequencies of all the three over expressed proteins. That led to the conclusion that amino acids e.g. alanine, glycine and valine that were energetically cheaper to produce were showing higher frequencies. This study would help in tracing the phylogenetic relationship between protein families.