Subunit communication in the tryptophan synthase α2β2 complex Effects of β subunit ligands on proteolytic cleavage of a flexible loop in the α subunit

FEBS Letters

Miles, Edith Wilson¹  Ruvinov, Sergei B.¹ 

[1] Laboratory of Biochemical Pharmacology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Building 8, Room 225, Bethesda, MD 20892, USA

关键词: Tryptophan synthase;    Subunit communication;    Allosteric mechanism;    Protein loop;    Proteolysis;    Ligand binding;   

DOI  :  10.1016/0014-5793(92)80246-D

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

To probe the structural basis for ligand-mediated communication between the α and β subunits in the tryptophan synthase α₂β₂ complex, we have determined the effects of ligands of the α and β subunits on proteolysis of a flexible loop in the α subunit. We find that addition of a ligand of the β subunit (l-serine, d-tryptophan, or l-tryptophan) in combination with a ligand of the α subunit (α-glycerol 3-phosphate) almost completely prevents the tryptic cleavage of the α subunit loop. Thus, the binding of a ligand to the β-site affects the conformation of the α subunit 25–30 Å distant.

【 授权许可】

Unknown