ATP and autophosphorylation driven conformational changes of HipA kinase revealed by ion mobility and crosslinking mass spectrometry
Toxin-antitoxin systems are genetic modules involved in a broad range of bacterial cellular processes including persistence, multidrug resistance and tolerance, biofilm formation, and pathogenesis. In type II toxin-antitoxin systems, both the toxin and antitoxin are proteins. In the prototypic Escherichia coli HipA-HipB module, the antitoxin HipB forms a complex with the protein kinase HipA and sequesters it in the nucleoid. HipA is then no longer able to phosphorylate glutamyl-tRNA-synthetase and this prevents the initiation of the forthcoming stringent response. Here we investigated the assembly of the Shewanella oneidensis MR-1 HipA-HipB complex using native electrospray ion mobility-mass spectrometry and chemical crosslinking combined with mass spectrometry. We revealed that the HipA autophosphorylation was accompanied by a large conformational change, and confirmed structural evidence that S. oneidensis MR-1 HipA-HipB assembly was distinct from the prototypic E. coli HipA-HipB complex.
KeywordsToxin-antitoxin system HipAB Ion mobility Chemical crosslinking Mass spectrometry
- 15.Black DS, Irwin B, Moyed HS. Autoregulation of hip, an operon that affects lethality due to inhibition of peptidoglycan or DNA synthesis. J Bacteriol. 1994;176(13):4081–91.Google Scholar