6V76

Crystal Structure of Human PKM2 in Complex with L-valine

6V76 の概要

• エントリーDOI: 10.2210/pdb6v76/pdb
• 分子名称: Pyruvate kinase PKM, CHLORIDE ION, POTASSIUM ION, ... (9 entities in total)
• 機能のキーワード: glycolytic enzyme, tetramer, amino acid binding, transferase
• 由来する生物種: Homo sapiens (Human)
• タンパク質・核酸の鎖数: 4
• 化学式量合計: 243234.94

構造登録者

Nandi, S.,Dey, M. (登録日: 2019-12-07, 公開日: 2020-03-18, 最終更新日: 2023-10-11)

主引用文献

Nandi, S.,Dey, M.
Biochemical and structural insights into how amino acids regulate pyruvate kinase muscle isoform 2.
J.Biol.Chem., 295:5390-5403, 2020

PubMed Abstract: Pyruvate kinase muscle isoform 2 (PKM2) is a key glycolytic enzyme involved in ATP generation and critical for cancer metabolism. PKM2 is expressed in many human cancers and is regulated by complex mechanisms that promote tumor growth and proliferation. Therefore, it is considered an attractive therapeutic target for modulating tumor metabolism. Various stimuli allosterically regulate PKM2 by cycling it between highly active and less active states. Several small molecules activate PKM2 by binding to its intersubunit interface. Serine and cysteine serve as an activator and inhibitor of PKM2, respectively, by binding to its amino acid (AA)-binding pocket, which therefore represents a potential druggable site. Despite binding similarly to PKM2, how cysteine and serine differentially regulate this enzyme remains elusive. Using kinetic analyses, fluorescence binding, X-ray crystallography, and gel filtration experiments with asparagine, aspartate, and valine as PKM2 ligands, we examined whether the differences in the side-chain polarity of these AAs trigger distinct allosteric responses in PKM2. We found that Asn (polar) and Asp (charged) activate PKM2 and that Val (hydrophobic) inhibits it. The results also indicate that both Asn and Asp can restore the activity of Val-inhibited PKM2. AA-bound crystal structures of PKM2 displayed distinctive interactions within the binding pocket, causing unique allosteric effects in the enzyme. These structure-function analyses of AA-mediated PKM2 regulation shed light on the chemical requirements in the development of mechanism-based small-molecule modulators targeting the AA-binding pocket of PKM2 and provide broader insights into the regulatory mechanisms of complex allosteric enzymes.

PubMed: 32144209
DOI: 10.1074/jbc.RA120.013030

実験手法

X-RAY DIFFRACTION (2.75 Å)