Evolutionary process of Glutamate Synthase Protein Family within the cyanobacteria: An In-silico Analysis

GS/GOGAT cycle is found in all organisms including cyanobacteria and is involved in the incorporation process of ammonium into carbon skeletons. Glutamate synthase (GOGAT) along with Glutamine synthetase (GS) is part of this GS/GOGAT pathway. GOGAT enzyme transfers the amide group of Glutamine to 2-oxogluterate to yield 2 molecules of glutamate which can further be used to make other amino acids. Since cyanobacteria is considered as one of the key orgnisms involved in shaping the course of evolution and ecological change throughout earth's history, we have analyzed gene and protein sequences of GOGAT enzyme for all cyanobacterial species to understand evolutionary process of this protein family and evaluate the role of this enzyme in observed high protein content of Arthrospira platensis. The multiple sequence analysis could identify cyanobacterial signature pattern of each of the important domains of GOGAT protein family which could be used as marker to identify domain. From the phylogenetic tree analysis, some horizontal gene transfer events were identified. Gene duplication and speciation events within cyanobacterial species were also identified through gene tree analysis.