1 Title 2 Discovery of a small molecule that inhibits bacterial ribosome biogenesis 3 4 Authors and Affiliations 5 Jonathan M. Stokes1, Joseph H. Davis2, Chand S. Mangat1, James R. Williamson2, and Eric D. Brown1* 6 7 1Michael G. DeGroote Institute for Infectious Disease Research, Department of Biochemistry and 8 Biomedical Sciences, McMaster University, Hamilton, Ontario, Canada, L8N 3Z5 9 2Department of Integrative Structural and Computational Biology, Department of Chemistry and The Skaggs 10 Institute for Chemical Biology, The Scripps Research Institute, La Jolla, CA 92037, USA 11 12 Contact 13 *Correspondence:
[email protected] 14 15 Competing Interests Statement 16 All authors declare no competing interests. 17 18 Impact Statement 19 We report the discovery of a small molecule inhibitor of bacterial ribosome biogenesis. The first probe of its 20 kind, this compound revealed an unexplored role for IF2 in ribosome assembly. 21 22 Major Subject Areas 23 Biochemistry; Microbiology and infectious disease 24 25 Keywords 26 Cold sensitivity; ribosome biogenesis; lamotrigine; translation initiation factor IF2 27 28 1 29 Abstract 30 While small molecule inhibitors of the bacterial ribosome have been instrumental in understanding protein 31 translation, no such probes exist to study ribosome biogenesis. We screened a diverse chemical collection 32 that included previously approved drugs for compounds that induced cold sensitive growth inhibition in the 33 model bacterium Escherichia coli. Among the most cold sensitive was lamotrigine, an anticonvulsant drug. 34 Lamotrigine treatment resulted in the rapid accumulation of immature 30S and 50S ribosomal subunits at 35 15°C. Importantly, this was not the result of translation inhibition, as lamotrigine was incapable of perturbing 36 protein synthesis in vivo or in vitro.