Crystal structure of Bacillus subtilis YabJ, a purine regulatory protein and member of the highly conserved YjgF family

Proc Natl Acad Sci U S A. 1999 Nov 9;96(23):13074-9. doi: 10.1073/pnas.96.23.13074.


The yabJ gene in Bacillus subtilis is required for adenine-mediated repression of purine biosynthetic genes in vivo and codes for an acid-soluble, 14-kDa protein. The molecular mechanism of YabJ is unknown. YabJ is a member of a large, widely distributed family of proteins of unknown biochemical function. The 1.7-A crystal structure of YabJ reveals a trimeric organization with extensive buried hydrophobic surface and an internal water-filled cavity. The most important finding in the structure is a deep, narrow cleft between subunits lined with nine side chains that are invariant among the 25 most similar homologs. This conserved site is proposed to be a binding or catalytic site for a ligand or substrate that is common to YabJ and other members of the YER057c/YjgF/UK114 family of proteins.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Bacillus subtilis / chemistry*
  • Bacillus subtilis / genetics
  • Bacterial Proteins / chemistry*
  • Crystallography, X-Ray
  • Humans
  • Models, Molecular
  • Molecular Sequence Data
  • Operon
  • Sequence Homology, Amino Acid


  • Bacterial Proteins
  • YabJ protein, Bacillus subtilis

Associated data

  • PDB/1QD9