The Hormel Institute’s CryoEM discovery may support new antibiotic

Using CryoEM technology, Dr. Bin Liu and his team at The Hormel Institute, University of Minnesota discovered how bacteria use gene transcription to produce the flagellum that allow them to move and swim. To know how bacteria control movement is critically important because this swimming ability is a way disease-causing bacteria can gain a foot-hold and become more difficult to eliminate. Researchers believe this study may provide a new drug-intervention site for antibiotics.

Dr. Bin Liu is head of the Transcription and Gene Regulation lab at The Hormel Institute and members of his lab, including a postdoc and former SURE intern, assisted in this research. Dr. Liu’s article, “Structural basis of bacterial σ28‐mediated transcription reveals roles of the RNA polymerase zinc‐binding domain” was published in The EMBO Journal, EMBO’s flagship journal with an international reputation for quality and originality.

Transcription is the first part of the process of how cells use DNA to make functional things. Dr. Liu studies transcription in disease causing bacteria, in which an important part is to understand how and why that process begins – transcription initiation.

In bacteria, different sigma factors dictate the transcription of specific groups of genes. For the research published in his current article, Dr. Liu and his team looked at the transcription initiation for a specific sigma factor that controls the production of flagellum, tiny microscopic threads extending from bacteria that allow them to move and swim. This specific sigma factor, σ28, is indispensable for bacteria that move to compete with other microorganisms and survive in adverse conditions like poor nutrition.

Using CryoEM technology, Dr. Liu and his team captured images that show a specific part of the cell, bacterial RNA polymerase (RNAP) β′-zinc-binding domain (ZBD), performing a novel role in transcription initiation that was not previously known. Combined with additional lab results, the researchers revealed that ZBD-relocation is a general regulatory mechanism employed by a broader set of sigma factors/promoters.