4QS8

Arabidopsis Hexokinase 1 (AtHXK1) structure in ligand-free form

Summary for 4QS8

• Entry DOI: 10.2210/pdb4qs8/pdb
• Related: 4QS7 4QS9
• Descriptor: Hexokinase-1 (2 entities in total)
• Functional Keywords: hexokinase, atp-dependent, sugar sensor, transferase
• Biological source: Arabidopsis thaliana (mouse-ear cress, thale-cress)
• Cellular location: Mitochondrion outer membrane; Single-pass membrane protein: Q42525
• Total number of polymer chains: 1
• Total formula weight: 51784.16

Authors

Feng, J.,Zhao, S.,Liu, L. (deposition date: 2014-07-03, release date: 2015-02-11, Last modification date: 2023-11-08)

Primary citation

Feng, J.,Zhao, S.,Chen, X.,Wang, W.,Dong, W.,Chen, J.,Shen, J.-R.,Liu, L.,Kuang, T.
Biochemical and structural study of Arabidopsis hexokinase 1
Acta Crystallogr.,Sect.D, 71:367-375, 2015

PubMed Abstract: Hexokinase 1 from Arabidopsis thaliana (AtHXK1) plays a dual role in glycolysis and sugar sensing for vital metabolic and physiological processes. The uncoupling of glucose signalling from glucose metabolism was demonstrated by the analysis of two mutants (AtHXK1(G104D) and AtHXK1(S177A)) that are catalytically inactive but still functional in signalling. In this study, substrate-binding experiments indicate that the two catalytically inactive mutants have a high affinity for glucose, and an ordered substrate-binding mechanism has been observed for wild-type AtHXK1. The structure of AtHXK1 was determined both in its inactive unliganded form and in its active glucose-bound form at resolutions of 1.8 and 2.0 Å, respectively. These structures reveal a domain rearrangement of AtHXK1 upon glucose binding. The 2.1 Å resolution structure of AtHXK1(S177A) in the glucose-bound form shows similar glucose-binding interactions as the wild type. A glucose-sensing network has been proposed based on these structures. Taken together, the results provide a structural explanation for the dual functions of AtHXK1.

PubMed: 25664748
DOI: 10.1107/S1399004714026091

Experimental method

X-RAY DIFFRACTION (1.798 Å)