Crystal Structure of Bacillus subtilis YabJ, a Purine Regulatory Protein and Member of the Highly Conserved YjgF Family

• Published in: Proceedings of the National Academy of Sciences - PNAS 1999-11, Vol.96 (23), p.13074-13079
• Main Authors: Sinha, Sangita, Rappu, Pekka, Lange, S. C., Mäntsälä, Pekka, Zalkin, Howard, Smith, Janet L.
• Format: Article
• Language: English
• Subjects: Amino Acid Sequence; Animals; Bacillus subtilis; Bacillus subtilis - chemistry; Bacillus subtilis - genetics; Bacteria; Bacterial Proteins - chemistry; Biochemistry; Biological Sciences; Crystallography, X-Ray; Crystals; Humans; Ligands; Models, Molecular; Molecular Sequence Data; Molecules; Monomers; Operon; Operons; Proteins; Repression; Sequence Homology, Amino Acid; Trimers; YabJ protein; YjgF protein
• ISSN: 0027-8424; 1091-6490
• DOI: 10.1073/pnas.96.23.13074

The yabJ gene in Bacillus subtillis 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- angstrom 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.