<h3>Title</h3>
<h3>Nucleic acid engineering as a toolbox for studying nucleic acids conformations and imaging small molecules in cells</h3>
<p><strong><span style="text-decoration: underline;">Abstract</span> :</strong></p>
<p style="margin: 0cm; margin-bottom: .0001pt; text-align: justify;">Nucleic acids’ biological functions largely depend on their structure in the native cellular environment. In addition to the classical double helical structure, nucleic acids adopt various secondary and tertiary structures like hairpin, pseudoknot, bulge, triplex, tetraplex (G-quadruplex and i-motif) etc. to perform their cellular functions. Biophysical techniques like fluorescence, NMR, EPR, X-ray have been used widely to study nucleic acids <em><span style="color: #0e101a;">in vitro</span></em>. However, understanding the structure-function relationship of nucleic acid motifs in the native cellular environment has remained a major challenge due to the paucity of chemical probes that can be used both in vitro and in vivo. Therefore, the development of biophysical tools, which will enable the probing of nucleic acid structure, dynamics and recognition properties in both cell-free and cellular environments, will be highly beneficial. In my talk, I will present the design, synthesis, and utilization of a dual-app responsive nucleoside probe composed of two labels (fluorescence and 19F NMR) to investigate a therapeutically relevant non-canonical DNA structure, e.g., G-quadruplex in live <em><span style="color: #0e101a;">Xenopus laevis</span></em> oocytes and probe metal ion-induced conformational switch in a viral RNA motif. In the 2nd part of my talk, I will be presenting my current research focused on RNA engineering as a synthetic biology tool for molecular imaging in bacteria. I will describe the development of genetically encodable RNA-based fluorescent biosensors for live-cell imaging of a bacterial metabolite. These biosensors are made of a riboswitch domain that changes conformation upon binding to a specific small-molecule ligand and a fluorogenic RNA aptamer. A crucial aspect of the applications of these riboswitch-based sensors is their turn-on kinetics. A comparison of the in vivo turn-on kinetics of different riboswitch-based sensors will also be discussed in my presentation.</p>