Genome scale identification, structural analysis, and classification of periplasmic binding proteins from Mycobacterium tuberculosis.

Periplasmic-binding proteins occupy the periplasmic space of bacteria and are involved in binding and transport of various ions, siderophores, and other diverse types of solutes. These proteins may be associated with membrane transport systems or may help in activation of signal transducers. There is limited information available on Mycobacterium tuberculosis (Mtb) periplasm-inhabiting proteins. In the present study, we have performed genome-wide identification and functional annotation of periplasmic-binding proteins of Mtb on the basis of signature characteristics and their functional motifs. 37 putative periplasmic-binding proteins were identified in Mtb proteome and categorized into different classes mainly known for their association with membrane transport and signaling pathways. Conclusively, this study adds 11 completely novel proteins to the periplasmic binding proteome of Mtb, which were not annotated as PBPs earlier. This study provides an overview of the periplasmic binding proteome of Mtb, which may be involved in various important patho-physiological functions of the bacteria. These proteins may serve as novel drug targets, which may lead to better treatment strategies against this deadly pathogen.