8apb
rotational state 1b of the Trypanosoma brucei mitochondrial ATP synthase dimer
Structural highlights
FunctionATPA_TRYBB Mitochondrial membrane ATP synthase (F(1)F(o) ATP synthase) produces ATP from ADP in the presence of a proton gradient across the membrane which is generated by electron transport complexes of the respiratory chain (PubMed:19436713, PubMed:29247468). F-type ATPases consist of two structural domains, F(1) - containing the extramembraneous catalytic core, and F(o) - containing the membrane proton channel, linked together by a central stalk and a peripheral stalk (PubMed:19436713, PubMed:29247468, PubMed:29440423). During catalysis, ATP synthesis in the catalytic domain of F(1) is coupled via a rotary mechanism of the central stalk subunits to proton translocation. Subunits alpha and beta form the catalytic core in F(1) (PubMed:19436713, PubMed:29440423). Rotation of the central stalk against the surrounding alpha(3)beta(3) subunits leads to hydrolysis of ATP in three separate catalytic sites on the beta subunits (Probable). Subunit alpha does not bear the catalytic high-affinity ATP-binding sites (PubMed:29440423). Contrary to the procyclic, insect form that requires F(1)F(o) ATP synthase for ATP synthesis, the bloodstream form relies on ATP hydrolysis by F(1)F(o) ATP synthase to maintain its mitochondrial membrane potential (PubMed:29247468).[1] [2] [3] Publication Abstract from PubMedMitochondrial ATP synthase forms stable dimers arranged into oligomeric assemblies that generate the inner-membrane curvature essential for efficient energy conversion. Here, we report cryo-EM structures of the intact ATP synthase dimer from Trypanosoma brucei in ten different rotational states. The model consists of 25 subunits, including nine lineage-specific, as well as 36 lipids. The rotary mechanism is influenced by the divergent peripheral stalk, conferring a greater conformational flexibility. Proton transfer in the lumenal half-channel occurs via a chain of five ordered water molecules. The dimerization interface is formed by subunit-g that is critical for interactions but not for the catalytic activity. Although overall dimer architecture varies among eukaryotes, we find that subunit-g together with subunit-e form an ancestral oligomerization motif, which is shared between the trypanosomal and mammalian lineages. Therefore, our data defines the subunit-g/e module as a structural component determining ATP synthase oligomeric assemblies. An ancestral interaction module promotes oligomerization in divergent mitochondrial ATP synthases.,Gahura O, Muhleip A, Hierro-Yap C, Panicucci B, Jain M, Hollaus D, Slapnickova M, Zikova A, Amunts A Nat Commun. 2022 Oct 11;13(1):5989. doi: 10.1038/s41467-022-33588-z. PMID:36220811[4] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
| ||||||||||||||||||
