Motion in Fructose-1,6-biphosphatase [fbp]

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

Structures
1FBT Conformation 1 [ PartsList ]
1TIP Conformation 1 [ PartsList ]

Description
The structure of the neutral form of fructose-1,6-bisphosphatase complexed with AMP (and MG) was determined and shown to have a different quaternary structure than that of the unliganded enzyme. Specifically, two major quaternary conformational changes are observed: (1) A twist of dimer C3-C4 about the molecular 2-fold axis p by roughly 19 degrees relataive to dimer C1-C2, and (2) a translation of approximately 1 A of the AMP domains. The conformational shift between the T and R allosteric forms induced by AMP binding is also observed to induce a large movment of residues in the AMP domain.Superimposition of the two structures show average C-alpha displacements over the entire FBP domain in these complexes of 0.35 A. Glu97, Glu97, and Asp121 shift over 1 A, while C-alpha positions for Asp118 and Glu280 are observed to move 0.5 and 0.3 A, respectively. The largest changes in the R to T transition occur in the interdimeric interface, mainly made up of helices H1, H2, and H3. The dimer C3-C4 undergoes a 19 degree twist, placing the upper H2 helix close to the lower H3 helix in the T form.

Particular values describing motion
Maximum Rotation (degrees) = 19 ((from article))
Experimental Methods = x (Traditional x-ray)
Creation Date = 19971130
Modification Date = 19971212

References
Ke HM, Liang JY, Zhang YP, Lipscomb WN (1991). Conformational transition of fructose-1,6-bisphosphatase: structure comparison between the AMP complex (T form) and the fructose 6-phosphate complex (R form). Biochemistry 30(18):4412-4420. [Medline info for 91214982]

GO terms associated with structures
Molecular functioncatalytic activity, ATP binding
Biological processfructose 2,6-bisphosphate metabolism, 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