5voz
From Proteopedia
Yeast V-ATPase in complex with Legionella pneumophila effector SidK (rotational state 3)
Structural highlights
Function[VATL2_YEAST] Proton-conducting pore forming subunit of the membrane integral V0 complex of vacuolar ATPase. V-ATPase is responsible for acidifying a variety of intracellular compartments in eukaryotic cells.[1] [2] [VATC_YEAST] Subunit of the peripheral V1 complex of vacuolar ATPase. Subunit C acts as a flexible stator that holds together the catalytic and the membrane sectors of the enzyme. Reversibly leaves the enzyme after glucose depletion, causing the catalytic subcomplex V1 to detach from the V0 section. Binds ATP and is likely to have a specific function in the catalytic activity of the catalytic sector. V-ATPase is responsible for acidifying a variety of intracellular compartments in eukaryotic cells.[3] [VATB_YEAST] Non-catalytic subunit of the peripheral V1 complex of vacuolar ATPase. V-ATPase is responsible for acidifying a variety of intracellular compartments in eukaryotic cells. It is an electrogenic proton pump that generates a proton motive force of 180 mv, inside positive and acidic, in the vacuolar membrane vesicles.[4] [VATA_YEAST] Catalytic subunit of the peripheral V1 complex of vacuolar ATPase. V-ATPase (vacuolar ATPase) is responsible for acidifying a variety of intracellular compartments in eukaryotic cells. It is an electrogenic proton pump that generates a proton motive force of 180 mV, inside positive and acidic, in the vacuolar membrane vesicles. It may participate in maintenance of cytoplasmic Ca(2+) homeostasis. This is a catalytic subunit.[5] PI-SceI is an endonuclease that can cleave at a site present in a VMA1 allele that lacks the derived endonuclease segment of the open reading frame; cleavage at this site only occurs during meiosis and initiates "homing", a genetic event that converts a VMA1 allele lacking VDE into one that contains it.[6] [VPH1_YEAST] Subunit of the integral membrane V0 complex of vacuolar ATPase essential for assembly and catalytic activity. Is present only in vacuolar V-ATPase complexes. Enzymes containing this subunit have a 4-fold higher ratio of proton transport to ATP hydrolysis than complexes containing the Golgi/endosomal isoform and undergo reversible dissociation of V1 and V0 in response to glucose depletion. V-ATPase is responsible for acidifying a variety of intracellular compartments in eukaryotic cells.[7] [8] [9] [VATF_YEAST] Subunit of the peripheral V1 complex of vacuolar ATPase essential for assembly or catalytic function. V-ATPase is responsible for acidifying a variety of intracellular compartments in eukaryotic cells. [VATE_YEAST] Subunit of the peripheral V1 complex of vacuolar ATPase essential for assembly or catalytic function. V-ATPase is responsible for acidifying a variety of intracellular compartments in eukaryotic cells. [VA0D_YEAST] Vacuolar ATPase is responsible for acidifying a variety of intracellular compartments in eukaryotic cells. The active enzyme consists of a catalytic V1 domain attached to an integral membrane V0 proton pore complex. This subunit is a non-integral membrane component of the membrane pore domain and is required for proper assembly of the V0 sector. Might be involved in the regulated assembly of V1 subunits onto the membrane sector or alternatively may prevent the passage of protons through V0 pores. [VATL1_YEAST] Proton-conducting pore forming subunit of the membrane integral V0 complex of vacuolar ATPase. V-ATPase is responsible for acidifying a variety of intracellular compartments in eukaryotic cells. It is an electrogenic proton pump that generates a proton motive force of 180 mv, inside positive and acidic, in the vacuolar membrane vesicles. [VA0E_YEAST] Subunit of the integral membrane V0 complex of vacuolar ATPase. V-ATPase is responsible for acidifying a variety of intracellular compartments in eukaryotic cells.[10] [VATH_YEAST] Vacuolar ATPases regulate the organelle acidity. This subunit is essential for activity, but not assembly, of the enzyme complex. [VATG_YEAST] Catalytic subunit of the peripheral V1 complex of vacuolar ATPase (V-ATPase). V-ATPase is responsible for acidifying a variety of intracellular compartments in eukaryotic cells. [VATO_YEAST] Proton-conducting pore forming subunit of the membrane integral V0 complex of vacuolar ATPase. V-ATPase is responsible for acidifying a variety of intracellular compartments in eukaryotic cells. [VATD_YEAST] Subunit of the peripheral V1 complex of vacuolar ATPase. V-ATPase is responsible for acidifying a variety of intracellular compartments in eukaryotic cells, thus providing most of the energy required for transport processes in the vacuolar system. Publication Abstract from PubMedIntracellular pathogenic bacteria evade the immune response by replicating within host cells. Legionella pneumophila, the causative agent of Legionnaires' Disease, makes use of numerous effector proteins to construct a niche supportive of its replication within phagocytic cells. The L. pneumophila effector SidK was identified in a screen for proteins that reduce the activity of the proton pumping vacuolar-type ATPases (V-ATPases) when expressed in the yeast Saccharomyces cerevisae. SidK is secreted by L. pneumophila in the early stages of infection and by binding to and inhibiting the V-ATPase, SidK reduces phagosomal acidification and promotes survival of the bacterium inside macrophages. We determined crystal structures of the N-terminal region of SidK at 2.3 A resolution and used single particle electron cryomicroscopy (cryo-EM) to determine structures of V-ATPase:SidK complexes at ~6.8 A resolution. SidK is a flexible and elongated protein composed of an alpha-helical region that interacts with subunit A of the V-ATPase and a second region of unknown function that is flexibly-tethered to the first. SidK binds V-ATPase strongly by interacting via two alpha-helical bundles at its N terminus with subunit A. In vitro activity assays show that SidK does not inhibit the V-ATPase completely, but reduces its activity by ~40%, consistent with the partial V-ATPase deficiency phenotype its expression causes in yeast. The cryo-EM analysis shows that SidK reduces the flexibility of the A-subunit that is in the 'open' conformation. Fluorescence experiments indicate that SidK binding decreases the affinity of V-ATPase for a fluorescent analogue of ATP. Together, these results reveal the structural basis for the fine-tuning of V-ATPase activity by SidK. Molecular basis for the binding and modulation of V-ATPase by a bacterial effector protein.,Zhao J, Beyrakhova K, Liu Y, Alvarez CP, Bueler SA, Xu L, Xu C, Boniecki MT, Kanelis V, Luo ZQ, Cygler M, Rubinstein JL PLoS Pathog. 2017 Jun 1;13(6):e1006394. doi: 10.1371/journal.ppat.1006394., eCollection 2017 Jun. PMID:28570695[11] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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