4xd7 | pdb_00004xd7
Structure of thermophilic F1-ATPase inhibited by epsilon subunit
Structural highlights
FunctionATPA_BACP3 Produces ATP from ADP in the presence of a proton gradient across the membrane. The alpha chain is a regulatory subunit.[HAMAP-Rule:MF_01346] Publication Abstract from PubMedF1 -ATPase (F1 ) is the catalytic sector in Fo F1 -ATP synthase that is responsible for ATP production in living cells. In catalysis, its three catalytic beta-subunits undergo nucleotide occupancy-dependent and concerted open-close conformational changes that are accompanied by rotation of the gamma-subunit. Bacterial and chloroplast F1 are inhibited by their own epsilon-subunit. In the epsilon-inhibited Escherichia coli F1 structure, the epsilon-subunit stabilizes the overall conformation (half-closed, closed, open) of the beta-subunits by inserting its C-terminal helix into the alpha3 beta3 cavity. The structure of epsilon-inhibited thermophilic F1 is similar to that of E. coli F1 , showing a similar conformation of the epsilon-subunit, but the thermophilic epsilon-subunit stabilizes another unique overall conformation (open, closed, open) of the beta-subunits. The epsilon-C-terminal helix 2 and hook are conserved between the two structures in interactions with target residues and in their positions. Rest of the epsilon-C-terminal domains are in quite different conformations and positions, and have different modes of interaction with targets. This region is thought to serve epsilon-inhibition differently. For inhibition, the epsilon-subunit contacts the second catches of some of the beta- and alpha-subunits, the N- and C-terminal helices, and some of the Rossmann fold segments. Those contacts, as a whole, lead to positioning of those beta- and alpha- second catches in epsilon-inhibition-specific positions, and prevent rotation of the gamma-subunit. Some of the structural features are observed even in IF1 inhibition in mitochondrial F1 . DATABASE: Structural data are available in the Worldwide Protein Data Bank database under the accession number 4XD7. Structure of a thermophilic F1 -ATPase inhibited by an epsilon-subunit: deeper insight into the epsilon-inhibition mechanism.,Shirakihara Y, Shiratori A, Tanikawa H, Nakasako M, Yoshida M, Suzuki T FEBS J. 2015 Aug;282(15):2895-913. doi: 10.1111/febs.13329. Epub 2015 Jun 19. PMID:26032434[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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