9HGO

Crystal Structure of the Coxiella burnetii E110Q Mutant 2-methylisocitrate lyase

Summary for 9HGO

• Entry DOI: 10.2210/pdb9hgo/pdb
• Descriptor: 2-methylisocitrate lyase, 1,2-ETHANEDIOL, CHLORIDE ION, ... (4 entities in total)
• Functional Keywords: prpb, methylisocitrate lyase, carbon-carbon lyase, ec 4.1.3.30, cytosolic protein
• Biological source: Coxiella burnetii
• Total number of polymer chains: 2
• Total formula weight: 69281.82

Authors

Stuart, W.,Isupov, M.,Harmer, N.J. (deposition date: 2024-11-20, release date: 2025-08-13)

Primary citation

Stuart, W.S.,Jenkins, C.H.,Ireland, P.M.,Isupov, M.N.,Norville, I.H.,Harmer, N.J.
Structure and catalytic mechanism of methylisocitrate lyase, a potential drug target against Coxiella burnetii.
J.Biol.Chem., 301:108517-108517, 2025

PubMed Abstract: We present a comprehensive investigation into the catalytic mechanism of methylisocitrate lyase, a potential drug target candidate against the zoonotic pathogen Coxiella burnetii, the causative agent of Q fever and a federal select agent. Current treatment regimens are prolonged, often with incomplete clearance of the pathogen. We utilized a structure-based bioinformatics pipeline to identify methylisocitrate lyase as a candidate therapeutic target against C. burnetii from a list of essential genes. WT C. burnetii methylisocitrate lyase has a k of 13.8 s (compared to 105 s for Salmonella enterica), and isocitrate inhibits with a K of 11 mM. We have determined the previously uncharacterized substrate-bound structure of this enzyme family, alongside product and inhibitor-bound structures. These structures of WT enzyme reveal that in the active state the catalytic C118 is positioned 2.98 Å from O5 of methylisocitrate and Arg152 moves toward the substrate relative to the inhibitor bound structure. Analysis of structure-based mutants reveals that Arg152 and Glu110 are both essential for catalysis. We suggest that Arg152 acts as the catalytic base that initiates the methylisocitrate lyase reaction. These results deepen our understanding of the catalytic mechanism of methylisocitrate lyase and could aid the development of new therapeutics against C. burnetii.

PubMed: 40250561
DOI: 10.1016/j.jbc.2025.108517

Experimental method

X-RAY DIFFRACTION (1.82 Å)