6I2P

Crystal structure of the Mycobacterium tuberculosis PknB kinase domain (L33E mutant) in complex with its substrate GarA

6I2P の概要

• エントリーDOI: 10.2210/pdb6i2p/pdb
• 分子名称: Serine/threonine-protein kinase PknB, Glycogen accumulation regulator GarA, UNK-UNK-UNK-UNK-UNK, ... (7 entities in total)
• 機能のキーワード: kinase, fha-domain protein, signaling protein
• 由来する生物種: Mycobacterium tuberculosis (strain ATCC 25618 / H37Rv); 詳細
• タンパク質・核酸の鎖数: 5
• 化学式量合計: 97476.74

構造登録者

Andre-Leroux, G.,Hindie, V.,Barilone, N.,Bellinzoni, M.,Alzari, P.M. (登録日: 2018-11-01, 公開日: 2019-05-22, 最終更新日: 2024-10-23)

主引用文献

Wagner, T.,Andre-Leroux, G.,Hindie, V.,Barilone, N.,Lisa, M.N.,Hoos, S.,Raynal, B.,Vulliez-Le Normand, B.,O'Hare, H.M.,Bellinzoni, M.,Alzari, P.M.
Structural insights into the functional versatility of an FHA domain protein in mycobacterial signaling.
Sci.Signal., 12:-, 2019

PubMed Abstract: Forkhead-associated (FHA) domains are modules that bind to phosphothreonine (pThr) residues in signaling cascades. The FHA-containing mycobacterial protein GarA is a central element of a phosphorylation-dependent signaling pathway that redirects metabolic flux in response to amino acid starvation or cell growth requirements. GarA acts as a phosphorylation-dependent ON/OFF molecular switch. In its nonphosphorylated ON state, the GarA FHA domain engages in phosphorylation-independent interactions with various metabolic enzymes that orchestrate nitrogen flow, such as 2-oxoglutarate decarboxylase (KGD). However, phosphorylation at the GarA N-terminal region by the protein kinase PknB or PknG triggers autoinhibition through the intramolecular association of the N-terminal domain with the FHA domain, thus blocking all downstream interactions. To investigate these different FHA binding modes, we solved the crystal structures of the mycobacterial upstream (phosphorylation-dependent) complex PknB-GarA and the downstream (phosphorylation-independent) complex GarA-KGD. Our results show that the phosphorylated activation loop of PknB serves as a docking site to recruit GarA through canonical FHA-pThr interactions. However, the same GarA FHA-binding pocket targets an allosteric site on nonphosphorylated KGD, where a key element of recognition is a phosphomimetic aspartate. Further enzymatic and mutagenesis studies revealed that GarA acted as a dynamic allosteric inhibitor of KGD by preventing crucial motions in KGD that are necessary for catalysis. Our results provide evidence for physiological phosphomimetics, supporting numerous mutagenesis studies using such approaches, and illustrate how evolution can shape a single FHA-binding pocket to specifically interact with multiple phosphorylated and nonphosphorylated protein partners.

PubMed: 31064884
DOI: 10.1126/scisignal.aav9504

実験手法

X-RAY DIFFRACTION (2.37 Å)