3K74

Disruption of protein dynamics by an allosteric effector antibody

3K74 の概要

• エントリーDOI: 10.2210/pdb3k74/pdb
• 関連するPDBエントリー: 1HCV 5DFR
• 分子名称: Dihydrofolate reductase, Nanobody (3 entities in total)
• 機能のキーワード: immunoglobulin, protein-nanobody complex, antibiotic resistance, methotrexate resistance, nadp, one-carbon metabolism, oxidoreductase, trimethoprim resistance
• 由来する生物種: Escherichia coli K-12; 詳細
• タンパク質・核酸の鎖数: 2
• 化学式量合計: 30570.49

構造登録者

Oyen, D.,Srinivasan, V.,Steyaert, J.,Barlow, J. (登録日: 2009-10-12, 公開日: 2010-10-20, 最終更新日: 2024-11-06)

主引用文献

Oyen, D.,Srinivasan, V.,Steyaert, J.,Barlow, J.N.
Constraining enzyme conformational change by an antibody leads to hyperbolic inhibition.
J.Mol.Biol., 407:138-148, 2011

PubMed Abstract: Although it has been known for many years that antibodies display properties characteristic of allosteric effectors, the molecular mechanisms responsible for these effects remain poorly understood. Here, we describe a single-domain antibody fragment (nanobody) that modulates protein function by constraining conformational change in the enzyme dihydrofolate reductase (DHFR). Nanobody 216 (Nb216) behaves as a potent allosteric inhibitor of DHFR, giving rise to mixed hyperbolic inhibition kinetics. The crystal structure of Nb216 in complex with DHFR reveals that the nanobody binds adjacent to the active site. Half of the epitope consists of residues from the flexible Met20 loop. This loop, which ordinarily oscillates between occluded and closed conformations during catalysis, assumes the occluded conformation in the Nb216-bound state. Using stopped flow, we show that Nb216 inhibits DHFR by stabilising the occluded Met20 loop conformation. Surprisingly, kinetic data indicate that the Met20 loop retains sufficient conformational flexibility in the Nb216-bound state to allow slow substrate turnover to occur.

PubMed: 21238460
DOI: 10.1016/j.jmb.2011.01.017

実験手法

X-RAY DIFFRACTION (1.95 Å)