1BWF: Escherichia Coli Glycerol Kinase Mutant With Bound Atp Analog Showing Substantial Domain Motion

Citation:
Abstract
Escherichia coli glycerol kinase (GK) displays "half-of-the-sites" reactivity toward ATP and allosteric regulation by fructose 1, 6-bisphosphate (FBP), which has been shown to promote dimer-tetramer assembly and to inhibit only tetramers. To probe the role of tetramer assembly, a mutation (Ser58-->Trp) was designed to sterically block formation of the dimer-dimer interface near the FBP binding site [Ormo, M., Bystrom, C., and Remington, S. J. (1998) Biochemistry 37, 16565-16572]. The substitution did not substantially change the Michaelis constants or alter allosteric regulation of GK by a second effector, the phosphocarrier protein IIAGlc; however, it eliminated FBP inhibition. Crystal structures of GK in complex with different nontransferable ATP analogues and glycerol revealed an asymmetric dimer with one subunit adopting an open conformation and the other adopting the closed conformation found in previously determined structures. The conformational difference is produced by a approximately 6.0 degrees rigid-body rotation of the N-terminal domain with respect to the C-terminal domain, similar to that observed for hexokinase and actin, members of the same ATPase superfamily. Two of the ATP analogues bound in nonproductive conformations in both subunits. However, beta, gamma-difluoromethyleneadenosine 5'-triphosphate (AMP-PCF2P), a potent inhibitor of GK, bound nonproductively in the closed subunit and in a putative productive conformation in the open subunit, with the gamma-phosphate placed for in-line transfer to glycerol. This asymmetry is consistent with "half-of-the-sites" reactivity and suggests that the inhibition of GK by FBP is due to restriction of domain motion.
PDB ID: 1BWFDownload
MMDB ID: 10228
PDB Deposition Date: 1998/9/23
Updated in MMDB: 2012/11
Experimental Method:
x-ray diffraction
Resolution: 3  Å
Source Organism:
Similar Structures:
Biological Unit for 1BWF: dimeric; determined by author and by software (PISA)
Molecular Components in 1BWF
Label Count Molecule
Proteins (2 molecules)
2
Glycerol Kinase(Gene symbol: glpK)
Molecule annotation
Chemicals (6 molecules)
1
2
2
2
3
2
* Click molecule labels to explore molecular sequence information.

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