Document Type

Article

Publication Date

8-2025

Keywords

glucokinases, hexokinases, phosphate binding, sulfate binding

Abstract

Here, we report the crystal structure of Escherichia coli glucokinase (GLK), which has phosphate bound in the cleft between the alpha and beta domains adjacent to the active site. A ternary complex consisting of GLK, glucose and phosphate is also reported in this work. Diffraction data were collected at 2.63 angstrom resolution for the phospate-bound form (R-work/R-free = 0.191/0.230) and at 2.54 angstrom resolution for the ternary complex (R-work/R-free = 0.202/0.258), both at 297 K. A B-factor analysis of the phosphate-bound GLK structure revealed consistently lower values for phosphate-interacting basic residues in the alpha 4, alpha 5 and alpha 9 helices, while significant root-mean-square deviation (r.m.s.d.) spikes indicated flexibility in regions preceding beta 1 and within the loop between the beta 5 and beta 6 sheets of the. domain. In the ternary complex, phosphate is bound adjacent to glucose, and the B factors for the alpha 4, alpha 5 and alpha 9 helices were further reduced, while r.m.s.d. spikes were observed at the end of the beta 10 sheet and within the alpha 6 helix of the beta-domain. This structural characterization suggests that phosphate could influence the activity of GLK by altering glucose binding and modulating interactions with a loop-interacting regulatory protein.

Comments

Web of Science

IUCr

Creative Commons License

Creative Commons Attribution 4.0 International License
This work is licensed under a Creative Commons Attribution 4.0 International License.

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