Three-dimensional structure of YaaE from Bacillus subtilis, a glutaminase implicated in pyridoxal-5'-phosphate biosynthesis.

Publication Type:

Journal Article

Authors:

Bauer, Jacob A; Bennett, Eric M; Begley, Tadhg P; Ealick, Steven E

Source:

J Biol Chem, Volume 279, Issue 4, p.2704-11 (2004)

Keywords:

Amino Acid Sequence, Bacillus subtilis, Bacterial Proteins, Binding Sites, Glutaminase, Models, Molecular, Molecular Sequence Data, Protein Binding, Protein Conformation, Pyridoxal Phosphate, Structure-Activity Relationship

Abstract:

<p>The structure of YaaE from Bacillus subtilis was determined at 2.5-A resolution. YaaE is a member of the triad glutamine aminotransferase family and functions in a recently identified alternate pathway for the biosynthesis of vitamin B(6). Proposed active residues include conserved Cys-79, His-170, and Glu-172. YaaE shows similarity to HisH, a glutaminase involved in histidine biosynthesis. YaaD associates with YaaE. A homology model of this protein was constructed. YaaD is predicted to be a (beta/alpha)(8) barrel on the basis of sequence comparisons. The predicted active site includes highly conserved residues 211-216 and 233-235. Finally, a homology model of a putative YaaD-YaaE complex was prepared using the structure of HisH-F as a model. This model predicts that the ammonia molecule generated by YaaE is channeled through the center of the YaaD barrel to the putative YaaD active site.</p>