1AG9

FLAVODOXINS THAT ARE REQUIRED FOR ENZYME ACTIVATION: THE STRUCTURE OF OXIDIZED FLAVODOXIN FROM ESCHERICHIA COLI AT 1.8 ANGSTROMS RESOLUTION.

1AG9 の概要

• エントリーDOI: 10.2210/pdb1ag9/pdb
• 分子名称: FLAVODOXIN, CALCIUM ION, CHLORIDE ION, ... (7 entities in total)
• 機能のキーワード: electron transport, reductive activation, flavodoxin, escherichia coli
• 由来する生物種: Escherichia coli
• タンパク質・核酸の鎖数: 2
• 化学式量合計: 40901.69

構造登録者

Hoover, D.M.,Ludwig, M.L. (登録日: 1997-04-04, 公開日: 1997-12-24, 最終更新日: 2024-05-22)

主引用文献

Hoover, D.M.,Ludwig, M.L.
A flavodoxin that is required for enzyme activation: the structure of oxidized flavodoxin from Escherichia coli at 1.8 A resolution.
Protein Sci., 6:2525-2537, 1997

PubMed Abstract: In Escherichia coli, flavodoxin is the physiological electron donor for the reductive activation of the enzymes pyruvate formate-lyase, anaerobic ribonucleotide reductase, and B12-dependent methionine synthase. As a basis for studies of the interactions of flavodoxin with methionine synthase, crystal structures of orthorhombic and trigonal forms of oxidized recombinant flavodoxin from E. coli have been determined. The orthorhombic form (space group P2(1)2(1)2(1), a = 126.4, b = 41.10, c = 69.15 A, with two molecules per asymmetric unit) was solved initially by molecular replacement at a resolution of 3.0 A, using coordinates from the structure of the flavodoxin from Synechococcus PCC 7942 (Anacystis nidulans). Data extending to 1.8-A resolution were collected at 140 K and the structure was refined to an Rwork of 0.196 and an Rfree of 0.250 for reflections with I > 0. The final model contains 3,224 non-hydrogen atoms per asymmetric unit, including 62 flavin mononucleotide (FMN) atoms, 354 water molecules, four calcium ions, four sodium ions, two chloride ions, and two Bis-Tris buffer molecules. The structure of the protein in the trigonal form (space group P312, a = 78.83, c = 52.07 A) was solved by molecular replacement using the coordinates from the orthorhombic structure, and was refined with all data from 10.0 to 2.6 A (R = 0.191; Rfree = 0.249). The sequence Tyr 58-Tyr 59, in a bend near the FMN, has so far been found only in the flavodoxins from E. coli and Haemophilus influenzae, and may be important in interactions of flavodoxin with its partners in activation reactions. The tyrosine residues in this bend are influenced by intermolecular contacts and adopt different orientations in the two crystal forms. Structural comparisons with flavodoxins from Synechococcus PCC 7942 and Anaebaena PCC 7120 suggest other residues that may also be critical for recognition by methionine synthase.

PubMed: 9416602

実験手法

X-RAY DIFFRACTION (1.8 Å)