Nilanjana Hazra, Ph.D

Key Scientific Discoveries / Contributions:​For decades, biology textbooks have taught the sigma cycle is a universal mechanism. The theory was that the sigma factor binds to RNA polymerase to start the transcription process but must be released (dissociate) for productive RNA synthesis and transition to transcription elongation. ​My research with key transcription biologists of the field - Jayanta Mukhopadhyay and Richard H. Ebright, as mentor and collaborator has fundamentally overturned this assumption.¤ ​Discovery of sigma retention: Our work demonstrated that in certain bacteria—specifically Mycobacterium tuberculosis and Bacillus subtilis—the sigma factors do not always detach from RNA polymerase.¤ ​The SigmaF Factor: Specifically, our research published in Nucleic Acids Research (2026) showed that while some factors are released, SigF remains stably bound to the RNA polymerase throughout the entire transcription process. ¤ ​Implications for Stress Response: This retention allows bacteria to ensure a sustained, rapid expression of stress-response genes, which is a key survival mechanism for Mycobacteria. ​Impact on Medicine and Science:​This discovery is significant because it shifts our understanding of bacterial physiology. By identifying that different sigma factors behave in unique ways rather than following a "universal" cycle, our work opens up new pathways for: ¤ Understanding the specific mechanisms TB uses to survive stress that can lead to the development of new antibiotics. ​¤ It provides a more intricate view of how organisms control gene expression in response to their environment.¤ It shows that transcriptional machinery has evolved diverse strategies across different bacterial species, rather than sticking to one single model based on E. coli Sig70.Technical expertise that emerged as an outcome of this research:¤ End-to-end workflow expertise: Construct design, mutagenesis, cloning and detailed molecular biology --- expression, purification and labelling of recombinant proteins --- plan, execute and analyze high functional assays such as protein-protein, protein-DNA interactions using EMSA, radioactive in-vitro transcription (IVT) and fluorescence based FRET / anisotropies. Co-IP/ChIP and qPCR analyses. ¤ Working pace and tone: Fast, clean and efficient workflows. Attained reproducibility by multiple attempts and rigorous troubleshooting. A positive 'Yes, And?' approach --- to planning, experimentation, analysis and starting over. ¤ The best takeaway was a simple mindset --- 'If you have to fail, fail fast.'