5HTK

Human Heart 6-Phosphofructo-2-Kinase/Fructose-2,6-Bisphosphatase (PFKFB2)

5HTK の概要

• エントリーDOI: 10.2210/pdb5htk/pdb
• 関連するPDBエントリー: 5HR5
• 分子名称: 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase 2, CITRATE ANION, ADENOSINE-5'-TRIPHOSPHATE, ... (9 entities in total)
• 機能のキーワード: human pfkfb2, transferase, hydrolase
• 由来する生物種: Homo sapiens (Human)
• タンパク質・核酸の鎖数: 2
• 化学式量合計: 120344.94

構造登録者

Crochet, R.B. (登録日: 2016-01-27, 公開日: 2016-11-16, 最終更新日: 2023-09-27)

主引用文献

Crochet, R.B.,Kim, J.D.,Lee, H.,Yim, Y.S.,Kim, S.G.,Neau, D.,Lee, Y.H.
Crystal structure of heart 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase (PFKFB2) and the inhibitory influence of citrate on substrate binding.
Proteins, 85:117-124, 2017

PubMed Abstract: The heart-specific isoform of 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase (PFKFB2) is an important regulator of glycolytic flux in cardiac cells. Here, we present the crystal structures of two PFKFB2 orthologues, human and bovine, at resolutions of 2.0 and 1.8 Å, respectively. Citrate, a TCA cycle intermediate and well-known inhibitor of PFKFB2, co-crystallized in the 2-kinase domains of both orthologues, occupying the fructose-6-phosphate binding-site and extending into the γ-phosphate binding pocket of ATP. This steric and electrostatic occlusion of the γ-phosphate site by citrate proved highly consequential to the binding of co-complexed ATP analogues. The bovine structure, which co-crystallized with ADP, closely resembled the overall structure of other PFKFB isoforms, with ADP mimicking the catalytic binding mode of ATP. The human structure, on the other hand, co-complexed with AMPPNP, which, unlike ADP, contains a γ-phosphate. The presence of this γ-phosphate made adoption of the catalytic ATP binding mode impossible for AMPPNP, forcing the analogue to bind atypically with concomitant conformational changes to the ATP binding-pocket. Inhibition kinetics were used to validate the structural observations, confirming citrate's inhibition mechanism as competitive for F6P and noncompetitive for ATP. Together, these structural and kinetic data establish a molecular basis for citrate's negative feed-back loop of the glycolytic pathway via PFKFB2. Proteins 2016; 85:117-124. © 2016 Wiley Periodicals, Inc.

PubMed: 27802586
DOI: 10.1002/prot.25204

実験手法

X-RAY DIFFRACTION (2.01 Å)