Motion in Glycogen Phosphorylase (GP) [gp]

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

Structures 1GPB Conformation 2 [ PartsList ] 9GPB Conformation 1 [ PartsList ]

Description Quaternary Structure Changes: In the low to high affinity transition (T to R), the two subunits in a GP dimer rotate relative to each other by ~10 degrees. There are two main contact points between the subunits: the tower helices and the Cap/alpha2 contact. The subunit rotation is perpendicular to the dimer twofold and occurs about the Cap/alpha2 contact. It moves together atoms in this region by ~1 A and moves them apart near the tower helices by ~3 A. The tower helix interface completely repacks, changing the helix packing angles by ~20 degrees. Tertiary Structure Changes: the change in orientation of the tower helices causes a loop near the active site (the 280s loop) to disorder in the R form. This prevents blockage of the active site.

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

References D Barford and L N Johnson (1989). The allosteric transition of glycogen phosphorylase. Nature. 340: 609-616. [Medline info for 89365154] L N Johnson and D Barford (1990). Glycogen Phosphorylase. J. Biol. Chem. 265: 2409-2412. [Medline info for 90153846] Lin K, Rath VL, Dai SC, Fletterick RJ, Hwang PK (1996). A protein phosphorylation switch at the conserved allosteric site in GP. Science 273(5281):1539-1542 [Medline info for 96365222]

Data and Graphics Movie and Info Page Movies and further information on GP (via UCSF)

GO terms associated with structures Molecular function phosphorylase activity Biological process carbohydrate metabolism

Morphs

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

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