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Functional Annotation of Uncharacterized Proteins of Listeria Monocytogenes.
Authors: Parvinder Kaur, Rhythm Gandhi, Harbinder Kaur, Sana Gupta, Ruchi Sachdeva
Number of views: 239
Listeria monocytogenes is a gram-positive, non-spore forming, facultatively anaerobic rod which is found in soil, water samples, silage, sewage, slaughterhouse waste, milk of normal and mastitic cows, human and animal faeces. L. monocytogenes has been implicated as the causative agent in several outbreaks of food-borne listeriosis. Recently sequenced genome of L. monocytogenes J1-220 has large number of protein encoding genes annotated as hypothetical proteins. Thus, keeping this in mind, we attempted to predict the functions of 30 randomly selected hypothetical proteins of L. monocytogenes J1-220 genome with the help of various analysis including domains prediction, remote homology search, fold recognition, investigation of transmembrane helices and functional partners. Functions of five proteins were successfully assigned based on the consistent predictions obtained from different analysis. A strong agreement was obtained regarding different structural and functional aspects of these proteins, thereby validating the annotation. These proteins were found to play critical roles in cellular processes such as membrane transport, signal transduction, host interaction and catalysis. Gene products unique to L. monocytogenes for which no function could be identified were eleven. For five proteins, partial information was obtained based on the results obtained from single analysis. Thus, functional annotation of hypothetical proteins has enhanced the L. monocytogenes genomic information and provided a useful basis for experimental design aiming to understand the mechanism of pathogenesis and drug target identification.