Structure of a Wbl protein and implications for NO sensing by M. tuberculosis

• DOI: 10.1038/s41467-017-02418-y
• Publication Date: 2017-12-18T16:49:03Z
• Authors: Bassam K. Kudhair; Andrea M. Hounslow; Matthew D. Rolfe; Jason C. Crack; Debbie M. Hunt; Roger S. Buxton; Laura J. Smith; Nick E. Le Brun; Michael P. Willia...; Jeffrey Green
• Keywords: Helix (gastropod); Sigma factor; Iron–sulfur cluster

Mycobacterium tuberculosis causes pulmonary (TB) and claims ~1.8 million human lives per annum. Host nitric oxide (NO) is important in controlling TB infection. M. WhiB1 a NO-responsive Wbl protein (actinobacterial iron-sulfur proteins first identified the 1970s). Until now, structure of has not been available. Here NMR structural model reveals that are four-helix bundles with core three α-helices held together by [4Fe-4S] cluster. The cluster required for formation complex major sigma factor (σA) reaction NO disassembles this complex. suggests loss (by nitrosylation) permits positively charged residues C-terminal helix to engage DNA binding, triggering reprogramming gene expression includes components virulence-critical ESX-1 secretion system.