Structural Characterization of Glycerol Kinase from the Thermophilic Fungus Chaetomium thermophilum.

Piotr Wilk,Grzegorz Dubin,Piotr Tokarz,Piotr H Małecki,Klaudia Woś,Przemysław Grudnik,Elżbieta Wątor,Katarzyna Kuśka

doi:10.3390/ijms21249570

Piotr Wilk, Grzegorz Dubin + Show 6 more

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https://doi.org/10.3390/ijms21249570

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Abstract

Glycerol is an organic compound that can be utilized as an alternative source of carbon by various organisms. One of the ways to assimilate glycerol by the cell is the phosphorylative catabolic pathway in which its activation is catalyzed by glycerol kinase (GK) and glycerol-3-phosphate (G3P) is formed. To date, several GK crystal structures from bacteria, archaea, and unicellular eukaryotic parasites have been solved. Herein, we present a series of crystal structures of GK from Chaetomium thermophilum (CtGK) in apo and glycerol-bound forms. In addition, we show the feasibility of an ADP-dependent glucokinase (ADPGK)-coupled enzymatic assay to measure the CtGK activity. New structures described in our work provide structural insights into the GK catalyzed reaction in the filamentous fungus and set the foundation for understanding the glycerol metabolism in eukaryotes.

Highlights

Glycerol metabolism provides a central link between sugar and fatty acid catabolism [1]
New structures described in our work provide structural insights into the glycerol kinase (GK) catalyzed reaction in the filamentous fungus and set the foundation for understanding the glycerol metabolism in eukaryotes
It is converted into glycerol-3-phosphate (G3P) by glycerol kinase (GK, Gut1p in Saccharomyces cerevisiae), G3P is transported into mitochondria where it is oxidized to dihydroxyacetone phosphate (DHAP) by glycerol-3-phosphate dehydrogenase (GPD2, Gut2p in S. cerevisiae) [2]

Summary

Introduction

Glycerol metabolism provides a central link between sugar and fatty acid catabolism [1]. Glycerol can serve as an energy source, providing one ATP molecule from one glycerol molecule. It is converted into glycerol-3-phosphate (G3P) by glycerol kinase (GK, Gut1p in Saccharomyces cerevisiae), G3P is transported into mitochondria where it is oxidized to dihydroxyacetone phosphate (DHAP) by glycerol-3-phosphate dehydrogenase (GPD2, Gut2p in S. cerevisiae) [2]. The glycerol catabolism serves as an alternative energy source but is important in processes related to signaling, respiration, and lipid synthesis [3,4]. Glycerol kinase (EC 2.7.1.30) catalyzes the transfer of phosphate moiety from ATP to glycerol to form glycerol 3-phosphate (G3P). The enzyme is conserved among prokaryotes and eukaryotes [5] (Figure 1A,B)

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