Molecular Probing and Phylogenetic Analysis of Glutamate synthase of Arthrobacter nicotianae.

Introduction: Glutamate synthase is an oxidoreduactase transaminating enzyme that catalyzes the conversion of L-glutamate to L-glutamine with the aid of cofactors like NADP, NAD, FMN, Fe and sulfur. Its activities are in part to regulate the levels of glutamate and glutamine in a manner dependent on energy (ATP) and metabolite, ammonia. Methods and results: In this study we were able to demonstrate the presence of glutamate synthase by employing PCR utilizing genomic DNA isolated from soil bacteria Arthrobacter nicotianae PR. Cloning, sequencing and alignment revealed glutamate synthase with conserved amino acid residues specific to this group of functional proteins. 3D analysis of the GltS using Cn3D 4.1 software revealed well conserved alpha and beta sheets that in part form the TIM barrel and cofactor bonding site. Amino acids that bind the phosphate group of the cofactor were revealed. Un-rooted phylogenetic tree revealed unique distant metabolic relationship, potential development and adaptation of Artherobacter nicotianae PR compared to other bacteria including strains in the Athrobacter group. Conclusion: The phylogenetic divergence of GltS in the matching bacteria suggests possible evolutionary pressure being exerted by the local environment among other factors