Expression, Purification and In Silico Studies of Cold Resistant Protein from Plant Growth Promoting Ps fluorescens Mutant CRPF1

The production of cold shock proteins constitutes an adaptive response in psychrotrophic and psychrophillic microorganisms to allow survival after cold shock. In the present study a small 10kDa cold resistant protein (CRP) was expressed and purified by immuno-affinty chromatography from CRPF1, a cold resistant mutant of Pseudomonas fluorescens. Sequence analysis and homology studies of cold resistant gene revealed 91% sequence homology with the Pseudomonas fluorescens Pf-5 gene encoding cold shock DNA-binding protein. Three dimensional computational model of CRP was found similar to the known structures of cold shock proteins. It was consisted of five-stranded β- barrel-fold and highly conserved ribonucleoprotein consensus sequences, RNP1 (KGFGFI) and RNP2 (VHF) motif on its surface. Functional characterization of purified protein confirmed the DNA binding property of protein. From the sequence analysis and functional characterization of protein, it was concluded that a low molecular weight, DNA -binding cold resistant protein is induced in CRPF1 that helps in the survival of mutant under low temperature stress conditions.