3M5C

Crystal structure of N-acetyl-L-ornithine transcarbamylase K302E mutant complexed with PALAO

3M5C の概要

• エントリーDOI: 10.2210/pdb3m5c/pdb
• 関連するPDBエントリー: 3M4J 3M4N 3M5D
• 分子名称: N-acetylornithine carbamoyltransferase, N~2~-acetyl-N~5~-(phosphonoacetyl)-L-ornithine, SULFATE ION, ... (4 entities in total)
• 機能のキーワード: transcarbamylase, transferase
• 由来する生物種: Xanthomonas campestris pv. campestris
• 細胞内の位置: Cytoplasm : Q8P8J2
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 40482.78

構造登録者

Li, Y.,Yu, X.,Allewell, N.M.,Tuchman, M.,Shi, D. (登録日: 2010-03-12, 公開日: 2010-07-28, 最終更新日: 2023-09-06)

主引用文献

Li, Y.,Yu, X.,Ho, J.,Fushman, D.,Allewell, N.M.,Tuchman, M.,Shi, D.
Reversible post-translational carboxylation modulates the enzymatic activity of N-acetyl-L-ornithine transcarbamylase.
Biochemistry, 49:6887-6895, 2010

PubMed Abstract: N-Acetyl-l-ornithine transcarbamylase (AOTCase), rather than ornithine transcarbamylase (OTCase), is the essential carbamylase enzyme in the arginine biosynthesis of several plant and human pathogens. The specificity of this unique enzyme provides a potential target for controlling the spread of these pathogens. Recently, several crystal structures of AOTCase from Xanthomonas campestris (xc) have been determined. In these structures, an unexplained electron density at the tip of the Lys302 side chain was observed. Using (13)C NMR spectroscopy, we show herein that Lys302 is post-translationally carboxylated. The structure of wild-type AOTCase in a complex with the bisubstrate analogue N(delta)-(phosphonoacetyl)-N(alpha)-acetyl-l-ornithine (PALAO) indicates that the carboxyl group on Lys302 forms a strong hydrogen bonding network with surrounding active site residues, Lys252, Ser253, His293, and Glu92 from the adjacent subunit either directly or via a water molecule. Furthermore, the carboxyl group is involved in binding N-acetyl-l-ornithine via a water molecule. Activity assays with the wild-type enzyme and several mutants demonstrate that the post-translational modification of lysine 302 has an important role in catalysis.

PubMed: 20695527
DOI: 10.1021/bi1007386

実験手法

X-RAY DIFFRACTION (1.85 Å)