Genome Annotation of Uncharacterized Protein in Corynebacterium Diphtheriae

Assigning functional information to hypothetical proteins in bacterial genomes is crucial for gaining insight into their proteomes. Corynebacterium diphtheriae is one of the most prominent human pathogens and the causative agent of the communicable disease diphtheria. The genome of the NCTC13129 strain (biotype gravis) consists of a single circular chromosome of 2 488 635 bp, with no plasmids, in which the presence of 13 putative pathogenicity islands (PAIs) was demonstrated. Many genes that could contribute to the pathogenicity of C. diphtheriae are found within these putative islands. Comparative genomics revealed that the core genome consists of 2320 protein-coding sequences of which 45 are pseudogenes. Diphtheria toxin is one of the most widely studied bacterial toxins. The current work suggests a computational approach to annotate the putative function of the Corynebacterium diphtheria. Over all 80 sequences were collected from the NCBI database. The genome annotation were performed by using NCBI, MOTIF SEARCH, SMART, BLAST, TM PRED, CRNPRED, STRING, SOSUI, PROTPARAM, PSORTB and PHYRE2. The result suggests that most of the uncharacterized proteins resemble more to the transport regulators and signal transducers. Functions are assigned to 5 proteins out of the 80 uncharacterized proteins in C. diphtheriae with this approach.3 out of 5 characterized proteins are predicted with confidence score above 98 % by using PHYRE2. Therefore, the prediction of the function of these uncharacterized proteins might be helpful to find out the potential therapeutic drug targets against this deadliest pathogen.