PMID:9843423

From EcoliWiki
Jump to navigation Jump to search
Citation

Ormö, M, Bystrom, CE and Remington, SJ (1998) Crystal structure of a complex of Escherichia coli glycerol kinase and an allosteric effector fructose 1,6-bisphosphate. Biochemistry 37:16565-72

Abstract

The three-dimensional structures of Escherichia coli glycerol kinase (GK) with bound glycerol in the presence and absence of one of the allosteric regulators of its activity, fructose 1,6-bisphosphate (FBP), at 3.2 and 3.0 A, are presented. The molecule crystallized in space group P41212, and the structure was solved by molecular replacement. The models were refined with good stereochemistry to final R-factors of 21.1 and 21.9%, respectively. A tetrameric arrangement of monomers was observed which was essentially identical to the proposed inactive tetramer II previously described [Feese, M. D., Faber, H. R., Bystrom, C. E., Pettigrew, D. W., and Remington, S. J. (1998) Structure (in press)]. However, the crystal packing in this form was especially open, permitting the FBP binding site to be occupied and identified. The crystallographic data revealed a most unusual type of FBP binding site formed between two glycine-arginine loops (residues 234-236) where one-half of the binding site is donated by each monomer at the regulatory interface. The molecule of FBP binds in two mutually exclusive modes on a noncrystallographic 2-fold axis at 50% occupancy each; thus, a tetramer of GK binds two molecules of FBP. Ionic interactions between the 1- and 6-phosphates of FBP and Arg 236 were observed in addition to hydrogen bonding interactions between the backbone amide of Gly 234 and the 6-phosphate. No contacts between the protein and the furanose ring were observed. Mutagenesis of Arg 236 to alanine drastically reduced the extent of inhibition of GK by FBP and lowered, but did not eliminate, the ability of FBP to promote tetramer association. These observations are consistent with the previously characterized mechanism of FBP inhibition of GK, in which FBP acts both to promote dimer-tetramer assembly and to inactivate the tetramers.

Links

PubMed Online version:10.1021/bi981616s

Keywords

Alanine/genetics; Allosteric Regulation; Arginine/genetics; Arginine/physiology; Binding Sites/genetics; Chromatography, Gel; Crystallization; Crystallography, X-Ray; Escherichia coli/enzymology; Fructosediphosphates/chemistry; Fructosediphosphates/metabolism; Glycerol Kinase/antagonists & inhibitors; Glycerol Kinase/chemistry; Glycerol Kinase/genetics; Glycerol Kinase/metabolism; Macromolecular Substances; Models, Molecular; Mutagenesis, Site-Directed; Solutions

Significance

You can help EcoliWiki by summarizing why this paper is useful

Useful Materials and Methods

You can help Ecoliwiki by describing the useful materials (strains, plasmids, antibodies, etc) described in this paper.

Annotations

<annotationlinks/>

EcoliWiki Links

Add links to pages that link here (e.g. gene, product, method pages)

References

See Help:References for how to manage references in EcoliWiki.