Indian Association for the Cultivation of Science
» Structure and Dynamics: Spectroscopy and Scattering (SDSS - 2023) » Hybrid Halide Perovskites 2023 » Notice No. 3.032/1032 dated 29.08.2023 on re-constitution of the Management Committee of IACS » Special Campaign 3.0 mandated by DST » DST Notification » Quantum Sensing & Quantum Metrology » A Conference on "Recent Trends In Condensed Matter Physics Related To Quantum Materials" » IACS Colloquium from the School of Physical Sciences by Prof. Anindya Das, Department of Physics, Indian Institute of Science, Bangalore on 23rd February 2024 (Friday) » International Conference on Catalysis (IC²-2024) » 75th Republic Day Celebration at IACS Premises on 26.01.2024 » National Science Day celebration at IACS on 28th February, 2024 » IACS Colloquium from School of Physical Sciences by Prof. Diptiman Sen, IISc Bangalore » SAIS Symposium 2024 on 1st & 2nd March 2024 » Admission to Integrated Bachelor's-Master's Program in Science and Master's/Integrated Master's-Ph.D. Program in Science - 2024 » Appointment of one Sports Officer on purely temporary and contractual basis (in Consultancy mode) initially for a period of two (2) years. » Last date of Applications/Nominations for appointment of Director has been extended up-to 30th April, 2024 » Admission to the joint M.Sc.-Ph.D. Program in “Chemical and Molecular Biology” for the academic year 2024-25 (IACS and IIT-KGP) » Observance of Swachhata Pakhwada-2024 at IACS from May 01,2024 to May 15,2024. » Schedule of Interview for PhD Admission (Autumn Semester 2024) for School of Applied and Interdisciplinary Sciences(SAIS) » Notice for in-operative PAN » Schedule of Interview for PhD Admission (Autumn Semester 2024)for School of Biological Sciences(SBS) » Schedule of Interview for PhD Admission (Autumn Semester 2024)for School of Chemical Sciences(SCS) » Schedule of Interview for PhD Admission (Autumn Semester 2024)for School of Mathematical and Computational Sciences (SMCS) » Schedule of Interview for PhD Admission (Autumn Semester 2024)for School of Physical Sciences (SPS)

Name : Ranjan Sen

Department :
Designation : Director
Contact : + 91 (0)33-2473-4688 (Ext: 1101)
Email :


Present Position:  Director, Indian Association for the Cultivation of Science (IACS).




Institute / University





SINP,  Calcutta University

Biophysics & Molecular biology




SINP, Calcutta

Biophysical Sciences

1st class



Calcutta University

Biophysics & Molecular biology

1st class



Calcutta University

Physics (Hons), Chemistry, Mathematics

1st class



6th April 2023-onwards: Director, IACS, Kolkata.

29th June 2020 – 11th August 2020: In-charge Director, CDFD, Hyderabad.

6th March 2016 - 30th October 2017: In-charge Director, CDFD, Hyderabad.

1st April 2016 - 30th July 2016: In-charge Director, NIAB, Hyderabad.

1st July 2017- 5th April 2023: Staff Scientist-VII, CDFD, Hyderabad.

24th April 2013 – 1st July 2017: Staff Scientist VI at CDFD, Hyderabad.

24th April 2009- 24th April 2013: Staff Scientist V at CDFD, Hyderabad

1st May 2005 – 24th April 2009: Staff Scientist IV at CDFD, Hyderabad.

21st Dec 2001- 1st May 2005: Staff Scientist III at CDFD, Hyderabad.

Training/ Research Experience

June 1998 –15th Dec. 2001: 2nd postdoctoral training as Visiting fellow at NICHD, NIH, Bethesda, USA (Area: Molecular Microbiology).

Dec.1995- April 1998:  1st postdoctoral training as Visiting Researcher at the National Institute of Genetics, Mishima, Japan (Biochemistry).  

Oct. 1991-Nov. 1995: Ph.D. training as Senior Research Fellow at SINP, Kolkata, India (Biophysics).   

Area of Specialization

Area of Specialization: Biological Sciences

Sub-areas: Biochemistry (protein and nucleic acid chemistry), Biophysics (bio-molecular conformations, interaction energetics, and kinetics), Microbiology (Bacterial Gene expression, Bacterial Genetics, and functional genomics), Synthetic biology (design of peptides from regulatory proteins)

Research Interests

1)    Mechanism and physiology of transcription termination and antitermination processes in E.coli.

2)    Synthetic Biology approaches to design peptide antimicrobials.

3)    Identifications of novel protein factors from mycobacteriophage genomic libraries capable of modulating the physiological process of Mycobacterium.

Research tools used in my laboratory:

  • Bacterial Genetics and allied in vivo tools.
  • Microbial genomics and high-resolution microscopy as analytical tools to understand in vivo Biochemistry.
  • In vitro Biochemistry to study nucleic acids, proteins, and their interactions.
  • Biophysical Chemistry including thermodynamics and kinetics of bio-molecular reactions using spectroscopy (Absorbance, Fluorescence, and CD), surface plasmon resonance, ITC, and fast kinetics techniques, like stopped-flow and quench-flow.
  • Fluorescence Microscopy of Bacterial proteins.

Research Collaboration

Prof Markus Wahl, Freie Universität Berlin, Germany (Cryo-EM).

Prof. Agnieszka Szalewska-Pałasz, Uniwersytet Gdański, Poland.

Prof. Udaydittya Sen, SINP, Kolkata (Crystallography).

Fellowships/Awards/ Recognition

  • 2022: DST JC Bose Fellowship
  • 2021: Fellow of West Bengal Academy of Science and Technology (FWAST).
  • 2019: DBT Tata Innovation Fellowship.
  • 2018: Fellow of Telangana Academy of Sciences (FTASc), Hyderabad.
  • 2018: Fellow of Indian Academy of Sciences (FASc), Bangalore, India.
  • 2018: Fellow of Indian National Science Academy (FNA), New Delhi, India.
  • 2016: Member, DST-PAC of Biophysics, Biochemistry, Molecular, and Microbiology task force.
  • 2011: Elected Fellow National Academy of Science (FNASc), Allahabad, India.
  • 2008-2013: DST-Swarnajayanti Fellowship.
  • 2008: Elected as a Guha Research Conference member.
  • 2007: DBT Bioscience Carrier Development Award.
  • 2007: Nominated Member ASBMB, USA.
  • 2003-2008: Wellcome Trust Senior Research Fellowship, UK.
  • 2002-2007: National Institute of Health, USA, GRIP (RO1) Research Fellowship.
  • 1998-2001: Fogarty visiting fellowship award, NIH, USA.
  • 1997: CREST visiting scientist award, Japan.
  • 1995: Visiting Scientist Award, Ministry of Education, Japan.
  • 1996: Life-membership Indian Biophysical Society.
  • 1990: SINP Senior Research Fellowship.
  • 1990: UGC/CSIR Fellowship.


1) ‘NOVEL SYNTHETIC PEPTIDES’; Indian Patent Application No. 201841048582 filed on June 26, 2020.

Important Publications

1.    Chhakchhuak, P. I. R. and Sen, R. (2022). In vivo regulation of bacterial Rho-dependent transcription termination by the nascent RNA. Journal of Biological Chemistry, 298(6) 102001. doi: 10.1016/j.jbc.2022.102001.

2.    Ghosh, G., Sharma, P. V., Kumar, A., Jain, S., and Sen, R. (2021). Design of novel peptide-inhibitors against the conserved bacterial transcription terminator, Rho. J. Biol. Chem. Apr 9:100653. doi: 10.1016/j.jbc.2021.100653.

3.    Said, N., Hilal, T., Sunday, N. D., Khatri, A., Bürger, J., Mielke, T. Belogurov, G. A., Loll, B., Sen, R., Artsimovitch, I. and Wahl, M. C. (2021). Steps toward translocation-independent RNA polymerase inactivation by terminator ATPase ρ. Science, Jan 1;371(6524): eabd1673.

4.    Pal, K., Yadav, M., Jain, S., Ghosh, B., Sen, R., and Sen, U. (2019). Vibrio cholerae YaeO is a structural homologue of RNA chaperone Hfq that inhibits Rho-dependent transcription termination by dissociating its hexameric state. Journal of Molecular Biology, 431(24), 4749-4766.

5.    Wahl, M., and Sen, R. (2019). Exploiting phage strategies to modulate bacterial transcription. Transcription, Oct 30:1-9.

6.    Jain, S., Gupta, R, and Sen, R. (2019) Rho-dependent transcription termination in bacteria recycles RNA polymerases stalled at the DNA lesions. Nature Communications, Mar 14; 10(1):1207. DOI: 10.1038/s41467-019-09146-5.

7.    Ghosh, G., Reddy, J. Sambhare, S. and Sen, R. (2018) A bacteriophage capsid protein is an inhibitor of a conserved transcription terminator of various bacterial pathogens. Journal of Bacteriology, 200(1): e00380-17, 1-16.

8.    Mitra, P., Ghosh, G., Hafeezunnisa, M., and Sen, R. (2017). Rho protein: mechanism and action. Annual Review of Microbiology, 71, 687-709.

9.    Vishalini, V., Agarawal, S., and Sen, R. (2016). Molecular basis of NusG-mediated regulation of Rho-dependent transcription termination in bacteria. Journal of Biological Chemistry. 291, 22386-22403.

10. Qayyum M. Z., Dey D., and Sen, R. (2016). Transcription elongation factor NusA is a negative regulator of Rho-dependent termination. Journal of Biological Chemistry, 291(15), 8090-8108.

11. Mishra, S., and Sen, R. (2015). N protein from lambdoid phages transforms NusA into an antiterminator by modulating NusA-RNA polymerase flap domain interactions. Nucleic Acids Research. 43(12):5744-58.

12. Shashni, R., Qayyum, M. Z., Vishalini, V., Dey, D., and Sen, R. (2014). Redundancy of primary RNA-binding functions of the bacterial transcription terminator, Rho. Nucleic Acids Research, 42(15):9677-90.

13. Mishra, S., Mohan, S., Godavarthi, S., and Sen, R. (2013).  The interaction surface of a bacterial transcription elongation factor required for complex formation with an antiterminator during transcription antitermination. Journal of Biological Chemistry, 288 (39), 28089–28103.

14. Ranjan, A., Banerjee, R., Sharma, S., Sen, U., and Sen, R. (2013). Structural and mechanistic basis of antitermination of Rho-dependent transcription termination by a bacteriophage capsid protein. Nucleic Acids Research, 41 (14):6839-6856.

15. Banerjee, R., Nath, S., Ranjan, A., Khamrui, K., Pani, B. Sen, R., and Sen, U. (2012). The first structure of Polarity Suppression protein, Psu from Enterobacteria phage P4, reveals a novel fold and a knotted dimer. Journal of Biological Chemistry. 287(53), 44667–44675.

16. Muteeb, G., Dey, D., Mishra, S., and Sen, R. (2012). A multi-pronged strategy by an antiterminator to overcome Rho-dependent termination.  Nucleic Acids Research, 40(22), 11213-11228.

17. Kalyani, B. S., Muteeb, G., Qayyum, M. Z., and Sen, R. (2011). Interaction with the nascent RNA is a prerequisite for the recruitment of Rho to the transcription elongation complex in vitro. Journal of Molecular Biology. 413, 548-560.

18. Chalissery, J., Muteeb, G., Nisha C. K., Mohan, S. Jisha, V, and Sen, R. (2011). Interaction surface of the transcription terminator Rho required to form a complex with the C-terminal domain of the antiterminator NusG. Journal of Molecular Biology, 405, 49-64.

19. Nisha, C. K., Ranjan, A., Kalyani, S., Wal, M., and Sen, R. (2010). A bacterial transcription terminator with inefficient molecular motor action but with a robust transcription termination function. Journal of Molecular Biology, 395, 966-982.

20. Pani, B., Ranjan, A., and Sen, R. (2009). Interaction surface of bacteriophage P4 protein Psu required for the complex formation with the transcription terminator Rho. Journal of Molecular Biology. 389. 647-660.

21. Velikodvorskaya, T, Komissarova, N. Sen, R. King, R. A., Banik-Maiti, S., and Weisberg, R. A. (2008). Inhibition of a Transcriptional Pause by RNA Anchoring to RNA polymerase. Molecular Cell, 31, 1683-694.

22. Dutta, D., Chalissery, J., and Sen, R. (2008). Transcription termination factor Rho prefers catalytically active elongation complex for releasing RNA. Journal of Biological Chemistry, 283(29), 20243-20251.

23. Cheeran, A., Kolli, N. and Sen, R. (2007). The Site of Action of the Antiterminator Protein N from the Lambdoid Phage H-19B. Journal of Biological Chemistry, 282(42), 30997-31007.

24. Chalissery, J., Banerjee, S., Bandey, I. and Sen, R. (2007). Transcription termination defective mutants of Rho: role of different functions of Rho in releasing RNA from the elongation complex. Journal of Molecular Biology. 371, 855–872.

25. Pani, B., Banerjee, S., Chalissery, J., Abhishek, M., Ramya, M. L., Suganthan, R., and Sen, R. (2006). Mechanism of inhibition of Rho-dependent transcription termination by bacteriophage P4 protein Psu. Journal of Biological Chemistry. 281 (36), 26491-26500.

26. Banerjee, S., Chalissery, J., Bandey, I, and Sen, R. (2006). Rho-dependent transcription termination. More questions than answers. Journal of Microbiology, 44(1):11-22.

27. Cheeran, A., Suganthan, R., Swapna, G., Bandey, I., Acharya, S., Nagarajaram, H. A. and Sen, R. (2005) E.coli RNA polymerase mutations impaired for H19B N specific transcription antitermination are located close to the upstream edge of RNA: DNA hybrid and beginning of RNA exit channel of elongation complex. Journal of Molecular Biology, 252, 28-43.

28. King, R.A., Markov, D., Sen, R., Severinov, K. and Weisberg, R. A. (2004) A conserved Zinc binding site in the largest subunit of DNA-dependent RNA polymerase modulates intrinsic transcription termination and antitermination but does not stabilize the elongation complex. Journal of Molecular Biology, 342(4): 1143-54.

29. Sen, R., King, R.A., Mzhavia, N., Madsen, P., and Weisberg, RW (2002).  Sequence-specific interaction of nascent antiterminator RNA with the Zn-finger motif of E.coli RNA polymerase. Molecular Microbiology, 46(1):215-22.

30. Susa, M., Sen R. and Shimamoto, N. (2002) Generality of the Branched Pathway in Transcription Initiation by Escherichia coli RNA Polymerase. Journal of Biological Chemistry. 3; 277(18): 15407-12.

31. Sen, R., King, R., and Weisberg, R. W. (2001). Modification of the properties of elongating RNA polymerase by persistent association with nascent antiterminator RNA.  Molecular Cell. 7(5): 993-1001.

32. Sen, R., Nagai, H., and Shimamoto, N. (2000).  RNA Polymerase-arrest at Lambda PR promoter during transcription initiation Journal of Biological Chemistry. 275(15), 10899-10904.

33. Sen, R., Nagai, H., Hernandez VJ, and Shimamoto, N. (1998).  Reduction in abortive transcription from the Lambda PR promoter by mutations in region 3 of the sigma-70 subunit of Escherichia coli RNA polymerase.  Journal of Biological Chemistry. 273(16), 9872-9877.

34. Majee, S., Sen, R., Guha, S., Bhattacharyya, D., and Dasgupta, D. (1997).  Differential interaction of the Mg+2 complexes of chromomycin A3 and mithramycin with poly(dG-dC).poly(dC-dG) and poly(dG).poly(dC).  Biochemistry, 36(8), 2291-2299.

35. Aich, P., Sen, R. and Dasgupta D. (1992).  Role of magnesium ion in the interaction between chromomycin A3 and DNA: binding of chromomycin A3-Mg+2 complexes with DNA. Biochemistry, 31(11), 2988-2997. 

Group Members

1. Mr. Ajay Khatri, SRF

2. Mr. Md. Saddam Hussain Ansari, SRF 

3. Dr. Passong Immanual R. Chhackchhuak, RA in TRC

Contact Us

IACS, 2A and B, Raja Subodh Mallick Road, Kolkata-32, West Bengal,

India.Phone: +91-33-24734688(Direct), +91-33-24734971(Extn:1101), Fax: +91-33-24836561