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Structure of E3 ligase SopA bound to ubiquitinStructure of E3 ligase SopA bound to ubiquitin
Structural highlights
FunctionSOPA_SALTY Effector proteins function to alter host cell physiology and promote bacterial survival in host tissues. This protein is an E3 ubiquitin ligase that interferes with host's ubiquitination pathway. Required for inducing polymorphonuclear leukocytes migration across the intestinal epithelium. Preferentially uses host UBE2D1 (UBCH5A), UBE2D2 (UBCH5B) and UBE2L3 (UBCH7) as E2 ubiquitin-conjugating enzymes.[1] [2] Publication Abstract from PubMedHECT E3 ubiquitin (Ub) ligases direct their modified substrates toward a range of cellular fates dictated by the specific form of monomeric or polymeric Ub (polyUb) signal that is attached. How polyUb specificity is achieved has been a longstanding mystery, despite extensive study ranging from yeast to human. Two outlying examples of bacterial "HECT-like" (bHECT) E3 ligases have been reported in the human pathogens Enterohemorrhagic Escherichia coli and Salmonella Typhimurium, but what parallels can be drawn to eukaryotic HECT (eHECT) mechanism and specificity had not been explored. Here, we expanded the bHECT family and identified catalytically active, bona fide examples in both human and plant pathogens. By determining structures for three bHECT complexes in their primed, Ub-loaded states, we resolved key details of the full bHECT Ub ligation mechanism. One structure provided the first glimpse of a HECT E3 ligase in the act of ligating polyUb, yielding a means to rewire the polyUb specificity of both bHECT and eHECT ligases. Through studying this evolutionarily distinct bHECT family, we have not only gained insight into the function of key bacterial virulence factors but also revealed fundamental principles underlying HECT-type Ub ligation. Bacterial mimicry of eukaryotic HECT ubiquitin ligation.,Franklin TG, Brzovic PS, Pruneda JN bioRxiv. 2023 Jun 5:2023.06.05.543783. doi: 10.1101/2023.06.05.543783. Preprint. PMID:37333152[3] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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