Journal Article

Zinc-binding to the cytoplasmic PAS domain regulates the essential WalK histidine kinase of Staphylococcus aureus

Shaikh, Nausad, Pulyani, Neha, Howden, Benjamin P., Seemann, Torsten, Morey, Jacqueline R., Maher, Megan J., Begg, Stephanie L., Bierbaum, Gabriele, McDevitt, Christopher A., Monk, Ian R., Sharkey, Liam K. R., Stinear, Timothy P., Winnen, Brit, Hvorup, Rikki, Gajdiss, Mike, Collins, Brett M., Udagedara, Saumya R., Kuiper, Michael, Pidot, Sacha J., Lee, Jean Y. H., King, Glenn F.

2019

Overview

WalKR (YycFG) is the only essential two-component regulator in the human pathogen Staphylococcus aureus . WalKR regulates peptidoglycan synthesis, but this function alone does not explain its essentiality. Here, to further understand WalKR function, we investigate a suppressor mutant that arose when WalKR activity was impaired; a histidine to tyrosine substitution (H271Y) in the cytoplasmic Per-Arnt-Sim (PAS CYT ) domain of the histidine kinase WalK. Introducing the WalK H271Y mutation into wild-type S. aureus activates the WalKR regulon. Structural analyses of the WalK PAS CYT domain reveal a metal-binding site, in which a zinc ion (Zn 2+ ) is tetrahedrally-coordinated by four amino acids including H271. The WalK H271Y mutation abrogates metal binding, increasing WalK kinase activity and WalR phosphorylation. Thus, Zn 2+ -binding negatively regulates WalKR. Promoter-reporter experiments using S. aureus confirm Zn 2+ sensing by this system. Identification of a metal ligand recognized by the WalKR system broadens our understanding of this critical S. aureus regulon. WalKR is an essential two-component regulator that controls peptidoglycan synthesis in the human pathogen Staphylococcus aureus . Here, the authors provide biochemical, structural, and functional evidence supporting that the binding of a zinc ion inhibits autophosphorylation and thus alters WalKR regulatory activity.

• Publisher: Nature Publishing Group UK,Nature Publishing Group,Nature Portfolio
• Subject: 38 / 38/35 / 38/44 / 45 / 45/70 / 45/77 / 631/326/41/2482 / 631/326/41/2536 / 631/326/421 / 631/45/612/1247 / Amino Acid Substitution / Amino acids / Bacterial Proteins - chemistry / Bacterial Proteins - genetics / Bacterial Proteins - metabolism / Binding sites / Cations, Divalent - metabolism / Histidine / Histidine - genetics / Histidine kinase / Histidine Kinase - chemistry / Histidine Kinase - genetics / Histidine Kinase - metabolism / Humanities and Social Sciences / Kinases / Molecular Dynamics Simulation / multidisciplinary / Mutation / Penicillin / Peptidoglycans / Phosphorylation / Protein-Serine-Threonine Kinases - chemistry / Protein-Serine-Threonine Kinases - genetics / Protein-Serine-Threonine Kinases - metabolism / Regulon - genetics / Science / Science (multidisciplinary) / Staphylococcus aureus / Staphylococcus aureus - genetics / Staphylococcus aureus - metabolism / Suppressor mutant / Tyrosine / Tyrosine - genetics / Zinc / Zinc - metabolism