Proteins play a major role in biochemical and biophysical features of living organisms and the knowledge of their function is crucial in the development of new drugs, agriculture productivity improvement, biofuel production and several industrial products derived biologically. In current annotation approach, functional prediction of unknown proteins such as hypothetical proteins present in various genomes is a challenging task to the biological community. This incomplete genome information causes gaps in the knowledge especially in the area of drug discovery and metabolic engineering. Hence, an integrated genome-scale re-annotation has been evolved, which is the most promising approach to predict the functions of unknown or hypothetical proteins. In this approach, along with BLAST many other tools output will be integrated for better understanding the function of a given protein sequence. In this review, we describe the integrated re-annotation approach methods that will be helpful in systems level study of microorganisms.
Keywords: Hypothetical protein, functional prediction, homology, sequence similarity, motif, folds, systems biology, Genome Projects, Hypothetical, BioCyc Genome Database, JCVI-CMR comprehensive Microbial Resource, PFP tool, LOMETS