Structural Analysis of the Hanks-Type Protein Kinase YabT From Bacillus subtilis Provides New Insights in its DNA-Dependent Activation
Journal article, 2019

YabT is a serine/threonine kinase of the Hanks family from Bacillus subtilis, which lacks the canonical extracellular signal receptor domain but is anchored to the membrane through a C-terminal transmembrane helix. A previous study demonstrated that a basic juxtamembrane region corresponds to a DNA-binding motif essential for the activation of YabT trans-autophosphorylation. YabT is expressed during spore development and localizes to the asymmetric septum where it specifically phosphorylates essential proteins involved in genome maintenance, such as RecA, SsbA, and YabA. YabT has also been shown to phosphorylate proteins involved in protein synthesis, such as AbrB and Ef-Tu, suggesting a possible regulatory role in the progressive metabolic quiescence of the forespore. Finally, cross phosphorylations with other protein kinases implicate YabT in the regulation of numerous other cellular processes. Using an artificial protein scaffold as crystallization helper, we determined the first crystal structure of this DNA-dependent bacterial protein kinase. This allowed us to trap the active conformation of the kinase domain of YabT. Using NMR, we showed that the basic juxtamembrane region of YabT is disordered in the absence of DNA in solution, just like it is in the crystal, and that it is stabilized upon DNA binding. In comparison with its closest structural homolog, the mycobacterial kinase PknB allowed us to discuss the dimerization mode of YabT. Together with phosphorylation assays and DNA-binding experiments, this structural analysis helped us to gain new insights into the regulatory activation mechanism of YabT.

crystallization chaperone

autophosphorylation

spore development

dimerization

regulatory mechanism

Author

Lei Shi

Chalmers, Biology and Biological Engineering, Systems and Synthetic Biology

Andrea Cavagnino

University Paris-Saclay

Jean-Luc Rabefiraisana

University Paris-Saclay

Noureddine Lazar

University Paris-Saclay

Ines Li de la Sierra-Gallay

University Paris-Saclay

Francoise Ochsenbein

University Paris-Saclay

Marie Valerio-Lepiniec

University Paris-Saclay

Agathe Urvoas

University Paris-Saclay

Philippe Minard

University Paris-Saclay

Ivan Mijakovic

Chalmers, Biology and Biological Engineering, Systems and Synthetic Biology

Sylvie Nessler

University Paris-Saclay

Frontiers in Microbiology

1664-302X (ISSN)

Vol. 9 3014

Subject Categories

Biochemistry and Molecular Biology

Structural Biology

Medical Biotechnology (with a focus on Cell Biology (including Stem Cell Biology), Molecular Biology, Microbiology, Biochemistry or Biopharmacy)

DOI

10.3389/fmicb.2018.03014

More information

Latest update

6/26/2019