4kv9
GTPase domain of Septin 10 from Schistosoma mansoni in complex with GDP
Structural highlights
FunctionSEP10_SCHMA Filament-forming GTP-binding protein. Lacks GTPase activity, which is likely due to absence of an essential threonine residue important for hydrolytic activity in septins. May be involved in membrane remodeling, potentially by its nucleotide-dependent cellular membrane association/dissociation ability (PubMed:24464615). Able to bind to phosphatidylinositol-4,5-bisphosphate (PIP2)-containing giant unilamellar vesicles (GUVs), which serve as a model of biological membranes. Self-assembles into ordered cage-like structures on the vesicle membrane. Binds also to 1,2-dioleoyl-sn-glycero-3-phospho-L-serine (DOPS)-containing vesicles suggesting the requirement for negatively charged membranes. Is also able to promote deformation of the GUVs (PubMed:27687162).[1] [2] Publication Abstract from PubMedSeptins are filament forming GTP-binding proteins involved in important cellular events such as cytokinesis, barrier formation and membrane remodeling. Here, we present two crystal structures of the GTPase domain of a Schistosoma mansoni septin (SmSEPT10); one bound to GDP and the other to GTP. The structures have been solved at an unprecedented resolution for septins (1.93 and 2.1 A respectively) which has allowed for unambiguous structural assignment of regions previously poorly defined. Consequently we provide a reliable model for functional interpretation and a solid foundation for future structural studies. On comparing the two complexes, we observe for the first time the phenomenon of a strand slippage in septins. Such slippage generates a front-back communication mechanism between the G and NC interfaces. This data provides a novel mechanistic framework for the influence of nucleotide binding to the GTPase domain, opening new possibilities for the study of the dynamics of septin filaments. Crystal structure of a Schistosoma mansoni septin reveals the phenomenon of strand slippage in septins dependent on the nature of the bound nucleotide.,Zeraik AE, Pereira HM, Santos YV, Brandao-Neto J, Spoerner M, Santos MS, Colnago LA, Garratt RC, Araujo AP, Demarco R J Biol Chem. 2014 Jan 24. PMID:24464615[3] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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