6s5t | pdb_00006s5t
Legionella pneumophila SidJ-Human calmodulin complex
Structural highlights
Disease[CALM2_HUMAN] Catecholaminergic polymorphic ventricular tachycardia;Brugada syndrome;Romano-Ward syndrome. The disease is caused by mutations affecting the gene represented in this entry. Mutations in CALM2 are the cause of LQT15. Function[CALM2_HUMAN] Calmodulin mediates the control of a large number of enzymes, ion channels, aquaporins and other proteins through calcium-binding. Among the enzymes to be stimulated by the calmodulin-calcium complex are a number of protein kinases and phosphatases. Together with CCP110 and centrin, is involved in a genetic pathway that regulates the centrosome cycle and progression through cytokinesis (PubMed:16760425). Mediates calcium-dependent inactivation of CACNA1C (PubMed:26969752). Positively regulates calcium-activated potassium channel activity of KCNN2 (PubMed:27165696).[1] [2] [3] Publication Abstract from PubMedThe family of bacterial SidE enzymes catalyses phosphoribosyl-linked (PR) serine ubiquitination and promotes infectivity of Legionella pneumophilia, a pathogenic bacterium causing Legionnaires' disease(1-3). SidEs share the genetic locus with the Legionella effector SidJ that spatiotemporally opposes their toxicity in yeast and mammalian cells, through an unknown mechanism(4-6). Deletion of SidJ leads to a significant defect in the growth of Legionella in both its natural host amoeba and in murine macrophages(4,5). Here, we demonstrate that SidJ is a glutamylase that modifies the catalytic glutamate in the mono-ADPribosyl transferase (mART) domain of SdeA thus blocking its ubiquitin (Ub) ligase activity. SidJ glutamylation activity requires interaction with calmodulin (CaM), a eukaryotic specific co-factor, and can be regulated by intracellular changes in Ca(2+) concentrations. The cryo-EM structure of SidJ/human apo-CaM complex revealed the architecture of this unique heterodimeric glutamylase. In infected cells, we show that SidJ mediates glutamylation of SidEs on the surface of Legionella-containing vacuoles (LCVs). Using quantitative proteomics, we also uncovered multiple host proteins as putative targets of SidJ-mediated glutamylation. Collectively, this study reveals the mechanism of SidE ligases inhibition by a SidJ/CaM glutamylase and opens new avenues for studying protein glutamylation, an understudied protein modification in higher eukaryotes. Inhibition of bacterial ubiquitin ligases by SidJ-calmodulin-catalysed glutamylation.,Bhogaraju S, Bonn F, Mukherjee R, Adams M, Pfleiderer MM, Galej WP, Matkovic V, Lopez-Mosqueda J, Kalayil S, Shin D, Dikic I Nature. 2019 Jul 22. pii: 10.1038/s41586-019-1440-8. doi:, 10.1038/s41586-019-1440-8. PMID:31330532[4] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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