Motion in Phosphofructokinase [pfkallo]

[ jump to morphs ]

Classification Known Subunit Motion, Involving Allostery [S-a-2]

Structures 1PFK Conformation 1 [ PartsList ] 5PFK Conformation 2

Description PFK is a tetramer of four identical subunits, arranged into two dimers. There is a large interface (~2200 sq. A) between subunits in each dimer, and a smaller interface (~1500 sq. A) between dimers. Quaternary Structure Changes: In the transition between high and low affinity forms, (R to T), the dimers rotate 7 degrees relative to each other. This causes changes in the smaller interface. A layer of water molecules bridging two beta-strands is expelled, leading to the creation of more hydrogen bonds between the dimers. Tertiary Structure Changes: A loop near the substrate binding site and the small dimer interface (the 6-F loop) changes shape considerably. There are also some small shearing motions of helices in each subunit (8 and 9).

Particular values describing motion Creation Date = 19970822 Modification Date = 19970822 Experimental Methods = x (Traditional x-ray)

References P R Evans (1991). Structural aspects of allostery. Curr. Opin. Struc. Biol. 1: 773-779. [Medline info for 95094298] P R Evans, G W Farrants and M C Lawrence (1986). Crystallographic structure of allosterically inhibited phosphofructokinase at 7 A resolution. J Mol Biol. 191: 713-720. [Medline info for 87112731] T Schirmer and P R Evans (1990). Structural basis of the allosteric behaviour of phosphofructokinase. Nature. 343: 140-145. [Medline info for 90114433]

Morphs

[ show all images ]

Best representative Morph Morph name Structure #1 Structure #2 Residues [ ] [ ]

---

Copyright 1995-2005 M. Gerstein, W. Krebs, S. Flores, N. Echols, and others
Email: Mark.Gerstein _at_ yale.edu