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CryoElectron Microscope leads to greater understanding of gene expression

Dr. Bin Liu, Assistant Professor and leader of the Transcription and Gene Regulation lab at The Hormel Institute, today published discoveries in two top journals.

Liu’s cutting-edge research is based on data and analysis made using the Institute’s Cryo-electron microscope and Liu’s expert utilization of the technology.

“The research focuses on the important understanding of how bacteria respond to toxic metal ions and antibiotics,” Liu said, who joined HI faculty in 2018 from Yale University. “It may be possible to target these MerR family regulators and help to find a strategy to overcome the antibiotic resistance issue, one of the biggest public health challenges of our time.”

The article “Structural basis of copper-efflux-regulator-dependent transcription activation” was published in ISCIENCE (2021) and the research team led by Dr. Bin Liu included Drs. W. Shi, B. Zhang, Y. Jiang, C. Liu, W. Zhou, M. Chen, Y. Yang, and Y. Hu.  ISCIENCE is a new interdisciplinary open-access journal from Cell Press that provides a platform for original research in the life, physical, and earth sciences. The article “Structural visualization of transcription activated by a multidrug-sensing MerR family regulator,” was published in Nature Communications (2021) and the research team led by Dr. Bin Liu included Drs. W. Shi, B. Zhang, C. Liu, W. Zhou, M. Chen, Y. Yang, and Y. Hu. Nature Communications is an open access journal from Nature Research that publishes high-quality research from all areas of the natural sciences.

Both projects, using cryo-electron microscopy, developed high resolution structures of MerR family regulator (CueR/EcmrR)-dependent transcription complexes and showed how MerR family regulators reshape the suboptimal spacer DNA to enable optimal promoter recognition and initiate transcription.

Cryo-EM — capturing images at near atomic resolution— help scientists determine the important molecular complexes in transcription. Transcription is the first step of gene expression, allowing scientists to observe and possibly then impact gene expression.

Prior to cryoEM many questions about how gene expression is regulated in cells remained largely inaccessible with existing tools. To observe individual molecules of DNA interacting with the proteins that initiate, carry out, and regulate transcription, better imaging technologies like CryoEM are necessary.

By determining the cryo-EM structures at average resolutions of a multidrug-sensing regulator (EcmrR)- and copper efflux regulator (CueR)-dependent transcription processes from promoter opening to transcription initiation to RNA elongation, Liu and his team answered the long-lasting question regarding the mechanisms of transcription regulation by MerR family factors.