Structure of F1-ATP ase from beef heart mitochondria

In the initial view, the crystallographic structure is shown as a Ca-backbone, with the subunits colored by chain. The bound nucleotides are shown as wireframe models, colored blue. The g-subunit projects from the cylinder formed by the 3 a, b-subunits at the bottom, which is the interface with Fo.

  1. The protein structure is shown as a Ca-backbone, colored by chain. Chains A, B, and C are a-subunits, colored dark-blue, blue, blue-green; chains D, E, F are b-subunits, colored green, green-yellow, yellow. The g-subunit is red. Nucleotides are shown as spacefilling models. Chain D (green) is bDP, and has a bound ADP; Chain E (green-yellow), which has no bound nucleotide, is subunit bE; Chain F (yellow) is bTP, and has a bound AMP-PNP. The a-subunits all have bound AMP-PNP (as an ATP analogue).
  2. Richardson cartoon of the protein, showing secondary structure, colored by chain. Chains A, B, and C are a-subunits, colored dark-blue, blue, blue-green; chains D, E, F are b-subunits, colored green, green-yellow, yellow. Bound nucleotides are shown as wireframe models.

    3. Please turn rotation off before going any further.

  3. The protein structure is shown as a spacefilling model, colored by chain. To view structure from the top, click on Rotate 90o about x-axis button below. Chains A, B, and C are a-subunits, colored dark-blue, blue, blue-green; chains D, E, F are b-subunits, colored green, green-yellow, yellow. The g-subunit is red.

    4. Set slabmode on (click on image with right mouse button to get menu; options) to see a slice through the structure. The depth is at about the level of the nucleotide binding domains. See frame at left for instructions.

  4. Rotate 90o about x-axis. Rotate -90o about x-axis.
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  6. Rotate 90o about z-axis. Rotate -90o about z-axis.

The g-subunit, and its role as an axle for the a,b-subunits.

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  1. View the g-subunit as a spacefilling model.
  2. Color g-subunit by residue polarity. Hydrophobic residues are white, neutral polar residues are green, basic residues are blue, acidic residues are red.
  3. Color the a,b-subunits by residue polarity. Hydrophobic residues are white, neutral polar residues are green, basic residues are blue, acidic residues are red.
  4. The configuration of the b-subunits around the g-subunit. Wayne Frasch has suggested that the "greasy bearing" noted by Abrahams et al. has a more specific functional role than implied in the original description. The interactions between the different b-subunits and g-subunit are quite different in the different configurations. In each case, a hydrophobic loop of b, containing residues 273-280, interacts with a specific hydrophobic patch on g, but this differs in the different configurations. Interaction for subunit b-DP is at the most C-terminal span, and is completely hydrophobic; for subunit b-TP, the interaction is ~5 Å further towards the N-terminus, and is "discouraged" by a polar patch (Ser-267, Gly-268) on g at this level, so that the interaction is weak; while for b-E the interaction is another ~4 Å towards the N-terminus, and is the predominantly hydrophobic interaction is strengthened by a H-bond to Thr-259 of g. In this configuration, additional contacts are found in the "catch-loop", composed of residues 311-320, which only in the b-E configuration, form at least 3 extra H-bonds with the g-subunit. This loop does not interact with g in the other configurations.

The conformation of the b-subunits.

  1. The b-subunits in cartoon, showing the different conformations with occupancy of the nucleotide binding site. Colors are as for 1 above. ANP-PNP shown white, ADP shown blue
  2. See bDP alone.
  3. See bE alone.
  4. See bTP alone.
  5. See ATP-binding site in bTP. The backbone is colored blue, atoms within 6.0 Å of the AMP-PNP (or ATP) are colored by CPK atom colors; the AMP-PNP is colored yellow. Waters are green. Note that the "ATP" in file 1e79.pdb is an ADP catalytic site.Click here to see the AMP-PNP colored by CPK atom colors.

The DCCD-inhibited structure

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  1. See DCCD-adduct (N-5-cyclohexyl-N-5-[(cyclohexylamino)carbonyl]glutamine; - derived from glutamate 199 in chain D) in bDP. ADP is shown as a spacefilling model, colored CPK.
  2. View the d-subunit as a spacefilling model.
  3. View the e-subunit as a spacefilling model.

References

  1. Abrahams, J.P., Leslie, A.G., Lutter, R. and Walker, J.E. (1994) Structure at 2.8 Å resolution of F1-ATPase from bovine heart mitochondria. Nature 370, 621-628
©Copyright 1996, Antony Crofts, University of Illinois at Urbana-Champaign, a-crofts@uiuc.edu