1JUB

The K136E mutant of lactococcus lactis dihydroorotate dehydrogenase A

1JUB の概要

• エントリーDOI: 10.2210/pdb1jub/pdb
• 関連するPDBエントリー: 1DOR 1JQV 1JQX 1JRB 1JRC 1JUE 2DOR
• 分子名称: dihydroorotate dehydrogenase A, MAGNESIUM ION, FLAVIN MONONUCLEOTIDE, ... (5 entities in total)
• 機能のキーワード: homodimer, alpha-beta barrel, flavoprotein, mutant enzyme, oxidoreductase
• 由来する生物種: Lactococcus lactis
• 細胞内の位置: Cytoplasm (By similarity): P54321
• タンパク質・核酸の鎖数: 2
• 化学式量合計: 69905.97

構造登録者

Norager, S.,Arent, S.,Bjornberg, O.,Ottosen, M.,Lo Leggio, L.,Jensen, K.F.,Larsen, S. (登録日: 2001-08-24, 公開日: 2003-09-09, 最終更新日: 2023-10-25)

主引用文献

Norager, S.,Arent, S.,Bjornberg, O.,Ottosen, M.,Lo Leggio, L.,Jensen, K.F.,Larsen, S.
Lactococcus lactis dihydroorotate dehydrogenase A mutants reveal important facets of the enzymatic function
J.Biol.Chem., 278:28812-28822, 2003

PubMed Abstract: Dihydroorotate dehydrogenases (DHODs) are flavoenzymes catalyzing the oxidation of (S)-dihydroorotate to orotate in the biosynthesis of UMP, the precursor of all other pyrimidine nucleotides. On the basis of sequence, DHODs can be divided into two classes, class 1, further divided in subclasses 1A and 1B, and class 2. This division corresponds to differences in cellular location and the nature of the electron acceptor. Herein we report a study of Lactococcus lactis DHODA, a representative of the class 1A enzymes. Based on the DHODA structure we selected seven residues that are highly conserved between both main classes of DHODs as well as three residues representing surface charges close to the active site for site-directed mutagenesis. The availability of both kinetic and structural data on the mutant enzymes allowed us to define the roles individual structural segments play in catalysis. We have also structurally proven the presence of an open active site loop in DHODA and obtained information about the interactions that control movements of loops around the active site. Furthermore, in one mutant structure we observed differences between the two monomers of the dimer, confirming an apparent asymmetry between the two substrate binding sites that was indicated by the kinetic results.

PubMed: 12732650
DOI: 10.1074/jbc.M303767200

実験手法

X-RAY DIFFRACTION (1.4 Å)