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6tmi

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Cryo-EM structure of Toxoplasma gondii mitochondrial ATP synthase dimer, peripheral stalk model

Structural highlights

6tmi is a 5 chain structure with sequence from Toxoplasma gondii GT1. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
Method:	Electron Microscopy, Resolution 3.5Å
Resources:	FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT

Function

S7UU80_TOXGG Produces ATP from ADP in the presence of a proton gradient across the membrane.[RuleBase:RU003551]

Publication Abstract from PubMed

Mitochondrial ATP synthase plays a key role in inducing membrane curvature to establish cristae. In Apicomplexa causing diseases such as malaria and toxoplasmosis, an unusual cristae morphology has been observed, but its structural basis is unknown. Here, we report that the apicomplexan ATP synthase assembles into cyclic hexamers, essential to shape their distinct cristae. Cryo-EM was used to determine the structure of the hexamer, which is held together by interactions between parasite-specific subunits in the lumenal region. Overall, we identified 17 apicomplexan-specific subunits, and a minimal and nuclear-encoded subunit-a. The hexamer consists of three dimers with an extensive dimer interface that includes bound cardiolipins and the inhibitor IF(1). Cryo-ET and subtomogram averaging revealed that hexamers arrange into ~20-megadalton pentagonal pyramids in the curved apical membrane regions. Knockout of the linker protein ATPTG11 resulted in the loss of pentagonal pyramids with concomitant aberrantly shaped cristae. Together, this demonstrates that the unique macromolecular arrangement is critical for the maintenance of cristae morphology in Apicomplexa.

ATP synthase hexamer assemblies shape cristae of Toxoplasma mitochondria.,Muhleip A, Kock Flygaard R, Ovciarikova J, Lacombe A, Fernandes P, Sheiner L, Amunts A Nat Commun. 2021 Jan 5;12(1):120. doi: 10.1038/s41467-020-20381-z. PMID:33402698^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

References

↑ Mühleip A, Kock Flygaard R, Ovciarikova J, Lacombe A, Fernandes P, Sheiner L, Amunts A. ATP synthase hexamer assemblies shape cristae of Toxoplasma mitochondria. Nat Commun. 2021 Jan 5;12(1):120. PMID:33402698 doi:10.1038/s41467-020-20381-z