Research Projects

Background and The gap areas: In case of eukaryotes, the members of the DEAD-box helicase family have been implicated in several types of cellular roles apart from ribosome assembly. They have been shown to be dysregulated in several types of cancer (Xing et al, 2019; Yu et al, 2021). The DEAD-box helicase could be of novel potential therapeutic importance. For instance, one of the DEAD-box helicase, DDX5 is the target of a small molecular cancer drug in clinical trials (Xing et al, 2019). Current studies indicate that DEAD box helicase proteins are also involved in antiviral innate immunity (Ali, 2021). The Dbp6 and Dbp9 are essential DEAD-box helicase proteins required for 27S rRNA processing. Whereas Spb4 is a nucleolar ATP-dependent RNA helicase protein required at a later step to synthesize 60S ribosomal subunits. Since many RNA helicases and intermediate chaperon protein have been characterised, still we lack the fundamental and mechanistic understanding of primitive stages of LSU assembly. Also how these DEAD box helicases play role in pre-rRNA folding, maturation and compacting with ribosomal proteins and early assembly factors? Therefore, I propose to study structural, mechanistic relay and dynamics of DEAD box helicases (Dbp6, Dbp9 and Spb4) with rRNA. Scientific Rationale: Significance Single particle Cryo-EM/ X-ray crystallography study would reveal the ribosome subunit intermediates that are formed in active/inactive DEAD box helicases would allow a better understanding of LSU biogenesis. Using structure information and biophysical techniques (like NMR and ITC), mechanistic relay, interaction dynamics and kinetics of DEAD box helicases (Dbp6, Dbp9 and Spb4) with rRNA will be studied in detail to understand accuracy and precision of these helicases at residual levels. Hypothesis: The proposed project would give comprehensive insights into modulated biogenesis of the eukaryotic 60S ribosome subunit. The structure of DEAD box RNA helicases would instigate their remodeler role in rRNA and RNP architecture. Biophysical studies would showcase basal interaction dynamics, its affinity and kinetic parameters Deliverable: A clear understanding of the assembly intermediates would promote small molecule discovery capable of stalling the ribosome assembly and preventing ribosome maturation under diseased conditions. The detailed study in light of the ribosome intermediates they tend to would result in a holistic knowledge of their function.