PDBsum entry 1kmh

Hydrolase

PDB id: 1kmh

Contents

Protein chains

477 a.a. *

467 a.a. *

Ligands

TTX

* Residue conservation analysis

PDB id:

1kmh

Name:

Hydrolase

Title:

Crystal structure of spinach chloroplast f1-atpase complexed with tentoxin

Structure:

Atpase alpha subunit. Chain: a. Synonym: atp synthase alpha chain. Atpase beta subunit. Chain: b. Synonym: atp synthase beta chain. Ec: 3.6.1.34

Source:

Spinacia oleracea. Spinach. Organism_taxid: 3562. Cellular_location: chloroplast. Cellular_location: chloroplast

Biol. unit:

Hexamer (from PQS)

Resolution:

3.40Å R-factor: 0.298 R-free: 0.319

Authors:

G.Groth

Key ref:

G.Groth (2002). Structure of spinach chloroplast F1-ATPase complexed with the phytopathogenic inhibitor tentoxin. Proc Natl Acad Sci U S A, 99, 3464-3468. PubMed id: 11904410 DOI: 10.1073/pnas.052546099

Date:

16-Dec-01 Release date: 13-Mar-02

Protein chain

P06450  (ATPA_SPIOL) -  ATP synthase subunit alpha, chloroplastic from Spinacia oleracea

Seq: 507 a.a.

Struc: 477 a.a.

Protein chain

P00825  (ATPB_SPIOL) -  ATP synthase subunit beta, chloroplastic from Spinacia oleracea

Seq: 498 a.a.

Struc: 467 a.a.*

* PDB and UniProt seqs differ at 4 residue positions (black crosses)

Enzyme reactions

• Enzyme class: Chains A, B: E.C.7.1.2.2 - H(+)-transporting two-sector ATPase.
• Reaction: ATP + H2O + 4 H⁺(in) = ADP + phosphate + 5 H⁺(out)

Molecule diagrams generated from .mol files obtained from the KEGG ftp site

reference

DOI no: 10.1073/pnas.052546099

Proc Natl Acad Sci U S A 99:3464-3468 (2002)

PubMed id: 11904410

Structure of spinach chloroplast F1-ATPase complexed with the phytopathogenic inhibitor tentoxin.

G.Groth.

ABSTRACT

Tentoxin, a natural cyclic tetrapeptide produced by phytopathogenic fungi from the Alternaria species affects the catalytic function of the chloroplast F(1)-ATPase in certain sensitive species of plants. In this study, we show that the uncompetitive inhibitor tentoxin binds to the alphabeta-interface of the chloroplast F(1)-ATPase in a cleft localized at betaAsp-83. Most of the binding site is located on the noncatalytic alpha-subunit. The crystal structure of the tentoxin-inhibited CF(1)-complex suggests that the inhibitor is hydrogen bonded to Asp-83 in the catalytic beta-subunit but forms hydrophobic contacts with residues Ile-63, Leu-65, Val-75, Tyr-237, Leu-238, and Met-274 in the adjacent alpha-subunit. Except for minor changes around the tentoxin-binding site, the structure of the chloroplast alpha(3)beta(3)-core complex is the same as that determined with the native chloroplast ATPase. Tentoxin seems to act by inhibiting inter-subunit contacts at the alphabeta-interface and by blocking the interconversion of binding sites in the catalytic mechanism.

Selected figure(s)

Figure 2.
Fig. 2. Location of tentoxin in the crystal structure of the chloroplast F[1]-ATPase. (A) Ribbon diagram of the structure of the chloroplast -subunit (blue) and -subunit (red) at the tentoxin-binding site. The inhibitor is shown in ball-and-stick representation. Both subunits are shown with their 3-fold crystallographic axis in vertical orientation, with the binding site facing the external medium. (B) Schematic representation of the molecular structure of a single chloroplast -pair. The structure is shown from the top as it would appear on the membrane; the 3-fold axis points toward the viewer. The bound inhibitory tentoxin molecule is drawn in cpk mode.

Figure 3.
Fig. 3. Comparison of different conformational states of the bovine mitochondrial - and -subunits to the chloroplast -complex containing tentoxin. (A) Schematic representation of the peptide backbone of three different conformations of the mitochondrial - and -subunits that represent different states of the catalytic cycle (12, 30). Both subunits were superimposed on their C[ ]-atoms. The [E], [DP], and [TP] states of the noncatalytic -subunit is shown in gray, the closed conformation of the catalytic -subunit ( [DP] and [TP]) is drawn in red, and the open [E]state is coloured in green. Positions of residues Arg-304 and Glu-67, equivalent to residues Arg-297 and Asp-83 that are arrested by the tentoxin molecule in the chloroplast structure (B), are indicated by red and black arrows, respectively. As indicated by the arrow on the right (A), a shift form the closed to the open conformation of the catalytic -subunit which occurs during the catalytic cycle is associated with a domain movement that involves the -interface at Arg-304- Glu-67.

Figures were selected by an automated process.