7MIS

Cryo-EM structure of SidJ-SdeC-CaM reaction intermediate complex

Summary for 7MIS

• Entry DOI: 10.2210/pdb7mis/pdb
• EMDB information: 23863
• Descriptor: Calmodulin-dependent glutamylase SidJ, Calmodulin, SdeC, ... (8 entities in total)
• Functional Keywords: sidj, sdec, cam, complex, intermediate, acyl, adenylate, legionella, ubiquitination, transferase, transferase-ligase complex, transferase/ligase
• Biological source: Legionella pneumophila; More
• Total number of polymer chains: 3
• Total formula weight: 218055.03

Authors

Osinski, A.,Black, M.H.,Pawlowski, K.,Chen, Z.,Li, Y.,Tagliabracci, V.S. (deposition date: 2021-04-17, release date: 2021-08-18, Last modification date: 2025-05-21)

Primary citation

Osinski, A.,Black, M.H.,Pawlowski, K.,Chen, Z.,Li, Y.,Tagliabracci, V.S.
Structural and mechanistic basis for protein glutamylation by the kinase fold.
Mol.Cell, 81:4527-, 2021

PubMed Abstract: The kinase domain transfers phosphate from ATP to substrates. However, the Legionella effector SidJ adopts a kinase fold, yet catalyzes calmodulin (CaM)-dependent glutamylation to inactivate the SidE ubiquitin ligases. The structural and mechanistic basis in which the kinase domain catalyzes protein glutamylation is unknown. Here we present cryo-EM reconstructions of SidJ:CaM:SidE reaction intermediate complexes. We show that the kinase-like active site of SidJ adenylates an active-site Glu in SidE, resulting in the formation of a stable reaction intermediate complex. An insertion in the catalytic loop of the kinase domain positions the donor Glu near the acyl-adenylate for peptide bond formation. Our structural analysis led us to discover that the SidJ paralog SdjA is a glutamylase that differentially regulates the SidE ligases during Legionella infection. Our results uncover the structural and mechanistic basis in which the kinase fold catalyzes non-ribosomal amino acid ligations and reveal an unappreciated level of SidE-family regulation.

PubMed: 34407442
DOI: 10.1016/j.molcel.2021.08.007

Experimental method

ELECTRON MICROSCOPY (2.8 Å)