9G69

Cryo-EM structure of CdaA-DAC domain in complex with GlmM

9G69 の概要

• エントリーDOI: 10.2210/pdb9g69/pdb
• EMDBエントリー: 51096
• 分子名称: Phosphoglucosamine mutase, Diadenylate cyclase, ADENOSINE-5'-TRIPHOSPHATE (3 entities in total)
• 機能のキーワード: cyclic-di-amp cyclace, inhibitor, complex, protein binding
• 由来する生物種: Lactococcus lactis subsp. lactis; 詳細
• タンパク質・核酸の鎖数: 4
• 化学式量合計: 162418.39

構造登録者

Drougkas, P.,Paulino, C.,Poolman, B. (登録日: 2024-07-18, 公開日: 2025-01-08, 最終更新日: 2025-01-15)

主引用文献

Foster, A.J.,Li, H.,Drougkas, P.,Schuurman-Wolters, G.K.,Ten Kate, J.,Paulino, C.,Poolman, B.
Membrane-embedded CdaA is required for efficient synthesis of second messenger cyclic di-AMP.
Commun Biol, 7:1710-1710, 2024

PubMed Abstract: Cyclic di-adenylate monophosphate (cyclic di-AMP) is an important second messenger in microorganisms. Cyclic di-AMP regulates bacterial cell volume and turgor via control of potassium and compatible solute transport but is also involved in many other processes, including the activation of the metazoan innate immune response to bacterial infections. We compare the activity of full-length membrane-embedded CdaA, the enzyme that synthesizes cyclic di-AMP, with the water-soluble catalytic domain CdaA-DAC. Purified CdaA from L. lactis was studied in the detergent-solubilized state, and in lipid nanodiscs and vesicles. We show that CdaA is tetrameric and the membrane-bound complex has more than 2-orders of magnitude higher activity than soluble CdaA-DAC. CdaA activity increases with pH but does not strongly depend on the salt or lipid content, factors that are crucial for the control of osmoregulatory transporters. Cryo-EM and in-silico structure prediction of CdaA show that the two DAC dimers engage in a head-to-head interaction, leading to cyclic-di-AMP formation. The inhibitor phosphoglucomutase prevents this active conformation. We observe dynamic flexibility between the catalytic and membrane domains, even in the presence of ATP or non-hydrolyzable substrate ApCpp. This is the first comprehensive functional and structural characterization of a full-length cyclic di-AMP-specific cyclase.

PubMed: 39739009
DOI: 10.1038/s42003-024-07420-x

実験手法

ELECTRON MICROSCOPY (4.84 Å)