From Protein to Structure: Shuimu BioSciences Solves Polθ-Novobiocin Complex with Cryo-EM

Cryo-Electron Microscopy (cryo-EM) has emerged as a revolutionary technique, propelling the field of structural biology into a new era. At the forefront of this transformation is Shuimu BioSciences, a leading global cryo-EM and AI platform. Recently, the company achieved a remarkable milestone by successfully resolving the high-resolution cryo-EM structure of the Polθ-Novobiocin complex, shedding light on the intricate interplay between this crucial DNA repair enzyme and its inhibitor.

The Principles of Cryo-EM: Unlocking Structural Insights

Cryo-EM operates on the principle of rapidly freezing biological samples in their native state, preserving their intricate structures. By bombarding these frozen samples with an electron beam, cryo-EM captures a myriad of two-dimensional projections, which can then be computationally reconstructed into three-dimensional density maps at near-atomic resolution.

This groundbreaking technique has revolutionized the study of macromolecular structures, allowing researchers to visualize proteins, nucleic acids, and their complexes without the need for crystallization, a longstanding challenge in X-ray crystallography. Cryo-EM's ability to capture these intricate structures in their native conformations has opened up new frontiers in drug discovery, enabling a deeper understanding of target-ligand interactions and paving the way for structure-based drug design.

Unraveling the Polθ-Novobiocin Complex

Polθ, a DNA polymerase involved in the repair of double-strand breaks, plays a crucial role in maintaining genomic integrity. Dysregulation of this enzyme has been implicated in various cancers, making it an attractive target for novel therapeutic interventions. Novobiocin, a coumarin-based antibiotic, has shown promising inhibitory activity against Polθ, but the molecular mechanisms underlying this interaction remained elusive.

The cryo-electron microscopy structures of apo-state Polθ-HLD (left) and Polθ-HLD in complex with novobiocin (right).

Leveraging the power of cryo-EM, Shuimu BioSciences' researchers succeeded in resolving the high-resolution structure of the Polθ-Novobiocin complex. This groundbreaking achievement unveiled the intricate details of how Novobiocin binds to Polθ, providing invaluable insights into the inhibitory mechanism and paving the way for the rational design of more potent and selective inhibitors.

The Cryo-EM Journey: From Sample Preparation to Structure Determination

Shuimu BioSciences' expertise in cryo-EM extends beyond the microscopy itself. The company's proficiency in protein science and sample preparation techniques ensured the successful isolation and purification of the Polθ-Novobiocin complex, a crucial step in obtaining high-quality structural data.

Once the sample was prepared, Shuimu BioSciences' state-of-the-art cryo-EM instruments, equipped with advanced detectors and computational resources, captured thousands of high-resolution images of the frozen complex. These images were then subjected to sophisticated image processing and three-dimensional reconstruction algorithms, culminating in the generation of the high-resolution cryo-EM structure.

Empowering Drug Discovery with Cryo-EM and AI

Shuimu BioSciences' success in resolving the Polθ-Novobiocin complex structure exemplifies the company's commitment to driving innovation in structural biology and drug discovery. By seamlessly integrating cryo-EM with artificial intelligence (AI) and computational platforms, Shuimu BioSciences offers a comprehensive solution for accelerating the development of novel therapeutics.

The company is using "Cryo-EM Single Particle Analysis" (Cryo-EM SPA) approach to combine cryo-EM structural determination, AI-driven computational platforms, and functional assays, enabling the rational design of potential drug candidates and the rapid evaluation of their potency and selectivity.

The Future of Structural Biology and Drug Discovery

Shuimu BioSciences' groundbreaking work in resolving the Polθ-Novobiocin complex structure represents a significant stride in the field of structural biology and drug discovery. As cryo-EM techniques continue to evolve, and the integration with AI and computational approaches deepens, the ability to elucidate intricate macromolecular structures and their interactions with potential drug candidates will pave the way for a new era of targeted therapies across a wide range of therapeutic areas.

By harnessing the power of cryo-EM and AI, Shuimu BioSciences is poised to play a pivotal role in accelerating the development of novel therapeutics, particularly in the realm of challenging protein targets. The company's pioneering efforts in structural biology and drug discovery are paving the way for a future where personalized and targeted treatments become a reality, ultimately contributing to the betterment of human health and well-being.

Guo, H., Wang, Y. X., Mao, J., Zhao, H., He, Y., Hu, Y., Li, J., Liu, Y., Guan, Z., Guo, A., Ni, X., Zhang, F., & Heng, J. (2023). Cryo-EM structure of DNA polymerase θ helicase domain in complex with inhibitor novobiocin. bioRxiv. https://doi.org/10.1101/2023.01.20.524915