@article{f9830e4a723a4c17bdc95b2768d137c3,
title = "Structural insights into the functional divergence of WhiB-like proteins in Mycobacterium tuberculosis",
abstract = "WhiB7 represents a distinct subclass of transcription factors in the WhiB-Like (Wbl) family, a unique group of iron-sulfur (4Fe-4S] cluster-containing proteins exclusive to the phylum of Actinobacteria. In Mycobacterium tuberculosis (Mtb), WhiB7 interacts with domain 4 of the primary sigma factor (σA4) in the RNA polymerase holoenzyme and activates genes involved in multiple drug resistance and redox homeostasis. Here, we report crystal structures of the WhiB7:σA4 complex alone and bound to its target promoter DNA at 1.55-{\AA} and 2.6-{\AA} resolution, respectively. These structures show how WhiB7 regulates gene expression by interacting with both σA4 and the AT-rich sequence upstream of the −35 promoter DNA via its C-terminal DNA-binding motif, the AT-hook. By combining comparative structural analysis of the two high-resolution σA4-bound Wbl structures with molecular and biochemical approaches, we identify the structural basis of the functional divergence between the two distinct subclasses of Wbl proteins in Mtb.",
keywords = "AT-hook, Wbl family, WhiB1, WhiB7, X-ray crystallography, antibiotic resistance, iron-sulfur cluster, transcription factor, σ",
author = "Tao Wan and Magdal{\'e}na Horov{\'a} and Beltran, {Daisy Guiza} and Shanren Li and Wong, {Huey Xian} and Zhang, {Li Mei}",
note = "Funding Information: We thank Dr. M.A. Wilson for thoughtful feedback on the manuscript, Dr. Elizabeth Campbell at the Rockefeller University for insightful discussions on the WhiB7-dependent transcriptional regulation, Dr. Wei Xie at the Sloan Kettering Institute for assistance with the structural refinement of the WhiB7:σA4-βtip:PwhiB7 complex, Dr. M. Kato-Maeda for the Mtb H37Rv genomic DNA, and Dr. Y. Sun for the plasmids used for site-directed mutagenesis in Msm. The authors thank the staff at beamlines 9-2 and 12-2 of SSRL for assistance during the X-ray diffraction data collection. This work was supported in part by the National Institutes of Health (grant R35 GM138157-01 to L.-M.Z.) and by a National Science Foundation CAREER award (CLP 1846908 to L.-M.Z.). The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health. Use of the Stanford Synchrotron Radiation Lightsource (SSRL), SLAC National Accelerator Laboratory, is supported by the U.S. Department of Energy (DOE), Office of Science, Office of Basic Energy Sciences, under contract no. DE-AC02-76SF00515. The SSRL Structural Molecular Biology Program is supported by the DOE Office of Biological and Environmental Research and by the National Institute of General Medical Sciences, National Institutes of Health (including grant P41GM103393). L.-M.Z. directed the project. L.-M.Z. T.W. and S.L. contributed to experimental design. T.W. M.H. D.G.B. and H.-X.W. conducted molecular biology work and expressed, purified, and characterized the proteins. T.W. carried out the crystallographic study, the EMSA experiment, and the antibiotic sensitivity test. S.L. performed the whiB7 deletion in Msm. T.W. and L.-M.Z. wrote the manuscript. All authors contributed to the manuscript preparation. The authors declare no competing interests. One or more of the authors of this paper self-identifies as an underrepresented ethnic minority in science. Funding Information: This work was supported in part by the National Institutes of Health (grant R35 GM138157-01 to L.-M.Z.) and by a National Science Foundation CAREER award ( CLP 1846908 to L.-M.Z.). The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health. Use of the Stanford Synchrotron Radiation Lightsource (SSRL), SLAC National Accelerator Laboratory, is supported by the U.S. Department of Energy (DOE), Office of Science, Office of Basic Energy Sciences , under contract no. DE-AC02-76SF00515 . The SSRL Structural Molecular Biology Program is supported by the DOE Office of Biological and Environmental Research and by the National Institute of General Medical Sciences, National Institutes of Health (including grant P41GM103393 ). Publisher Copyright: {\textcopyright} 2021 Elsevier Inc.",
year = "2021",
month = jul,
day = "15",
doi = "10.1016/j.molcel.2021.06.002",
language = "English (US)",
volume = "81",
pages = "2887--2900.e5",
journal = "Molecular Cell",
issn = "1097-2765",
publisher = "Cell Press",
number = "14",
}