Molecular basis for CRISPR-associated transposons and RNA-guided transcriptional regulation

Our research is dedicated to elucidating the molecular mechanisms of RNA-guided biological systems, with a focus on CRISPR-associated transposons (CASTs) and emerging RNA-guided gene regulation functions. Leveraging our expertise in single-particle cryo-electron microscopy and a broad array of biochemical and functional assays, we aim to dissect the complex interactions and structural dynamics in these natural systems. Our recent work has advanced our understanding of diverse CRISPR-Cas systems, highlighting the structural basis for target recognition and enzyme activation. We have also made progress in studying the assembly of transpososomes that facilitate DNA transposition within CASTs. The proposed research will explore the molecular basis underlying targeted DNA insertion by CASTs, using Type I-B systems as model systems. Key questions include the structural dynamics of transpososome assembly, the mechanism of directional DNA insertion, the role of ATP hydrolysis in transposition, and a detailed understanding of target specificity. The insights gained will inform the rational design of simpler, more efficient systems. Additionally, we will investigate the structural basis of emerging RNA-guided gene regulation functions, which hold potential for developing programmable gene regulation tools. Supported by the flexibility of the MIRA mechanism, our goal is to deepen our understanding of RNA-guided systems, thereby driving the development of next-generation genome editing tools and expanding their potential applications in both therapeutic and basic research contexts. Project Number: 1R35GM158248-01 | Fiscal Year: 2025 | NIH Institute/Center: National Institute of General Medical Sciences (NIGMS) | Principal Investigator: Leifu Chang | Institution: PURDUE UNIVERSITY, WEST LAFAYETTE, IN | Award Amount: $501,917 | Activity Code: R35 | Study Section: Maximizing Investigators' Research Award B Study Section[MRAB] View on NIH RePORTER: https://reporter.nih.gov/project-details/11090616