Related Experiment Video
Updated: Jun 17, 2026

Unravelling the Function of a Bacterial Effector from a Non-cultivable Plant Pathogen Using a Yeast Two-hybrid Screen
Published on: January 20, 2017
Walkmycin B targets WalK (YycG), a histidine kinase essential for bacterial cell growth
Ario Okada1, Masayuki Igarashi, Toshihide Okajima
1Department of Bioscience, Graduate School of Agriculture, Kinki University, Nara, Japan.
Abstract:
The WalK (a histidine kinase)/WalR (a response regulator, aka YycG/YycF) two-component system is indispensable in the signal transduction pathway for the cell-wall metabolism of Bacillus subtilis and Staphylococcus aureus. The inhibitors directed against WalK would be expected to have a bactericidal effect. After we screened 1368 culture broths of Streptomyces sp. by a differential growth assay, walkmycin A, B and C, which were produced by strain MK632-100F11, were purified using silica-gel column chromatography and HPLC. In this paper, the chemical structure of the major product (walkmycin B) was determined to be di-anthracenone (C(44)H(44)Cl(2)O(14)), which was very similar to BE40665A. MICs of walkmycin B against B. subtilis and S. aureus were 0.39 and 0.20 microg ml(-1), and IC(50) measurements against WalK were 1.6 and 5.7 microM, respectively. To clarify the affinity between WalK and walkmycin B, surface plasmon resonance was measured to obtain the equilibrium dissociation constant, K(D1), of 7.63 microM at the higher affinity site of B. subtilis WalK. These results suggest that walkmycin B inhibits WalK autophosphorylation by binding to the WalK cytoplasmic domain.
More Related Videos
Related Concept Videos
Cytoskeletal Proteins in Bacteria
Chemotaxis in E. coli
cAMP-dependent Protein Kinase Pathways
Inhibition of Cdk Activity
M-Cdk Drives Transition Into Mitosis
Cyclin-dependent kinases, or Cdks, work in concert with cyclins to control cell cycle transitions. M-Cdk, a complex of Cdk1 bound to M cyclin, is a well-known example of this coordinated control that drives the transition from the G2 to the M phase.
M cyclin...
Anaphase Promoting Complex

