We are glad to announce that Ramakrishna Mission Vivekananda Educational and Research Institute (RKMVERI) will be conducting a special colloquium on “Novel proteins and peptides from bacteriophages with therapeutic potential” on 02 June 2025, 12 Noon at Seminar Hall, Narendrapur Campus.

Speaker : Dr. Ranjan Sen,  Centre For DNA Fingerprinting and Diagnostics (CDFD), Hyderabad
 Co-ordinator: Prof. Abhijit Chakrabarti

Abstract

Bacteriophages or phage proteins are weapons for killing bacteria. Phages target the host bacterial machinery of transcription, replication, translation, etc. They also encode lysins and lysozymes that lyse the bacterial cell wall. These proteins were evolved to take over the bacteria and for their propagation. These proteins are tools of Synthetic Biology to design novel weapons of bacterial destruction and various other biotechnological applications such as gene-editing, molecular cloning, etc.

Earlier, we characterized the Psu protein from phage P4 which is an inhibitor of bacterial Rho-dependent termination, and designed peptides from the c-terminal helix of a bacteriophage coat protein Psu, an anti-transcription terminator Rho. These peptides mimicked the anti-Rho function of Psu but through a distinct mechanism. These peptides can bind to DNA and function as transcription repressors like other nuclear-associated proteins (1-4). 

We further explored and mined a mycobacteriophage genome library (5) to source novel proteins i) toxic to mycobacterium and ii) Rho-inhibitor proteins against the E. coli Rho.  We characterized nucleic acid binding protein G49 (of phage Che12) (6), a phage Xis-protein derivative Gp36+ (of phage D29), and a synthetic protein evolved from the fusion of two phage proteins. We also identified genome DNA fragments containing Gp54 and Gp55 proteins of phage D29 having anti-Rho termination activity. Bioinformatics analyses predicted Gp54 to be a phosphoesterase, and Gp55 an RNAP-binding protein. We hypothesized that Gp54 moonlights as a Rho-binding protein. Further, biochemical characterizations are in progress to understand the mechanism of action of all these mycobacteriophage proteins.

References

1. Pani, et al. (2006).  Journal of Biological Chemistry. 281 (36), 26491-26500.

2. Ranjan et al. (2013). Nucleic Acids Research, 41 (14):6839-6856.

3. Ghosh et al. (2021).  Journal of Biological Chemistry, Jan-Jun;296:100653. doi: 10.1016 / j.jbc. 2021.100653.

4. Sharma et al., (2023) Journal of Biological Chemistry, 299(12), 105373; December. 

5. Singh et al, (2019).  Microbiology, Jul; 165(7):722-736.

6. Husain et al. (2023). International Journal of Biological Macromolecules. 236, 124025.

Keywords: Bacteriophage proteins, Psu, Rho, Gp49, Gp36+