Crystal structure of the Mg·ADP-inhibited state of the yeast F1c10-ATP synthase.

ABSTRACT: The F(1)c(10) subcomplex of the yeast F(1)F(0)-ATP synthase includes the membrane rotor part c(10)-ring linked to a catalytic head, (??)(3), by a central stalk, ???. The Saccharomyces cerevisiae yF(1)c(10)·ADP subcomplex was crystallized in the presence of Mg·ADP, dicyclohexylcarbodiimide (DCCD), and azide. The structure was solved by molecular replacement using a high resolution model of the yeast F(1) and a bacterial c-ring model with 10 copies of the c-subunit. The structure refined to 3.43-? resolution displays new features compared with the original yF(1)c(10) and with the yF(1) inhibited by adenylyl imidodiphosphate (AMP-PNP) (yF(1)(I-III)). An ADP molecule was bound in both ?(DP) and ?(TP) catalytic sites. The ?(DP)-?(DP) pair is slightly open and resembles the novel conformation identified in yF(1), whereas the ?(TP)-?(TP) pair is very closed and resembles more a DP pair. yF(1)c(10)·ADP provides a model of a new Mg·ADP-inhibited state of the yeast F(1). As for the original yF(1) and yF(1)c(10) structures, the foot of the central stalk is rotated by ?40 ° with respect to bovine structures. The assembly of the F(1) central stalk with the F(0) c-ring rotor is mainly provided by electrostatic interactions. On the rotor ring, the essential cGlu(59) carboxylate group is surrounded by hydrophobic residues and is not involved in hydrogen bonding.

SUBMITTER: Dautant A 

PROVIDER: S-EPMC2937982 | biostudies-literature | 2010 Sep

REPOSITORIES: biostudies-literature