Related Experiment Video
Updated: Jun 16, 2026

Escherichia coli -Based Complementation Assay to Study the Chaperone Function of Heat Shock Protein 70
Published on: March 8, 2024
Structure and biochemical analyses suggest that PrkA/YeaG protein of Thermus thermophilus functions as a putative
Masayuki Torii1, Ryo Kanno2, Akira Mizoguchi3
1Graduate School of Science, Osaka Metropolitan University, 3-3-138 Sugimoto, Sumiyoshi-ku, Osaka 558-8585, Japan.
Abstract:
Protein phosphorylation, a key post-translational modification, is mediated by various protein kinases. The bacterial PrkA/YeaG is recognized as an atypical protein kinase, but its activity remains elusive. This study investigated the structural and functional characteristics of a PrkA/YeaG homologue, TpkB, from Thermus thermophilus HB8. Using cryo-electron microscopy, the structures of TpkB in apo and AMPPNP-bound forms were determined, revealing a hexameric ring architecture characteristic of AAA + superfamily proteins. The TpkB protomer is comprised of an N-terminal domain, an ATPase domain and an LID domain. The ATPase domain contains conserved sequence motifs associated with ATPase activity, whereas the other domains present a novel fold. TpkB exhibits structural similarity to MoxR family proteins, which possess chaperone-like functions in conjunction with von Willebrand factor A (vWA) domain proteins. Structural and gene neighbourhood analyses suggested a functional link between PrkA/YeaG proteins and vWA domain proteins. Biochemical analyses demonstrated that TpkB exhibited ATPase activity and chaperone-like activity, but lacked detectable protein kinase activity. These findings establish TpkB as a novel member of the AAA+ superfamily with potential chaperone functions, providing new insights into the PrkA/YeaG family.
Related Concept Videos
Molecular Chaperones and Protein Folding
The...
Molecular Chaperones and Protein Folding
The...
Bacterial Protein Maturation
Diversity of Archaea III
Diversity of Archaea IV
Other Stress Responses in Bacteria

