Tetramer formation of Bacillus subtilis YabJ protein that belongs to YjgF/YER057c/UK114 family

Biosci Biotechnol Biochem. 2021 Feb 18;85(2):297-306. doi: 10.1093/bbb/zbaa037.


Bacillus subtilis YabJ protein belongs to the highly conserved YjgF/YER057c/UK114 family, which has a homotrimeric quaternary structure. The dominant allele of yabJ gene that is caused by a single amino acid mutation of Ser103Phe enables poly-γ-glutamic acid (γPGA) production of B. subtilis under conditions where the cell-density signal transduction was disturbed by the loss of DegQ function. X-ray crystallography of recombinant proteins revealed that unlike the homotrimeric wild-type YabJ, the mutant YabJ(Ser103Phe) had a homotetrameric quaternary structure, and the structural change appeared to be triggered by an inversion of the fifth β-strand. The YabJ homotetramer has a hole that is highly accessible, penetrating through the tetramer, and 2 surface concaves as potential ligand-binding sites. Western blot analyses revealed that the conformational change was also induced in vivo by the Ser103Phe mutation.

Keywords: Bacillus subtilis; X-ray crystallographic structure; YabJ; YjgF/YER057c/UK114; gain-of-function mutation.

MeSH terms

  • Bacillus subtilis / metabolism*
  • Bacterial Proteins / chemistry*
  • Bacterial Proteins / metabolism
  • Conserved Sequence
  • Models, Molecular
  • Protein Multimerization*
  • Protein Structure, Quaternary


  • Bacterial Proteins
  • YabJ protein, Bacillus subtilis
  • YjgF protein, Bacteria