Structural Analysis of Binding Determinants of Salmonella typhimurium Trehalose-6-phosphate Phosphatase Using Ground-State Complexes
Year: 2020
Type: article
Abstract: Trehalose-6-phosphate phosphatase (T6PP) catalyzes the dephosphorylation of trehalose 6-phosphate (T6P) to the disaccharide trehalose. The enzyme is not present in mammals but is essential to the viability of multiple lower organisms as trehalose is a critical metabolite, and T6P accumulation is toxic. Hence, T6PP is a target for therapeutics of human pathologies caused by bacteria, fungi, and parasitic nematodes. Here, we report the X-ray crystal structures of Salmonella typhimurium T6PP ( St T6PP) in its apo form and in complex with the cofactor Mg 2+ and the substrate analogue trehalose 6-sulfate (T6S), the product trehalose, or the competitive inhibitor 4- n -octylphenyl α- d -glucopyranoside 6-sulfate (OGS). OGS replaces the substrate phosphoryl group with a sulfate group and the glucosyl ring distal to the sulfate group with an octylphenyl moiety. The structures of these substrate-analogue and product complexes with T6PP show that specificity is conferred via hydrogen bonds to the glucosyl group proximal to the phosphoryl moiety through Glu123, Lys125, and Glu167, conserved in T6PPs from multiple species. The structure of the first-generation inhibitor OGS shows that it retains the substrate-binding interactions observed for the sulfate group and the proximal glucosyl ring. The OGS octylphenyl moiety binds in a unique manner, indicating that this subsite can tolerate various chemotypes. Together, these findings show that these conserved interactions at the proximal glucosyl ring binding site could provide the basis for the development of broad-spectrum therapeutics, whereas variable interactions at the divergent distal subsite could present an opportunity for the design of potent organism-specific therapeutics.
Source: Biochemistry
Institutions: Boston University, University of New Mexico
Language: English
Subfield: Structural Biology
Domain: Life Sciences
Open Access status: green
Funders: U.S. Department of Energy, National Institutes of Health, Office of Science, National Institute of General Medical Sciences, National Institute of Allergy and Infectious Diseases, Basic Energy Sciences, Biological and Environmental Research, Office of Research Infrastructure Programs, National Institutes of Health, Brookhaven National Laboratory, SLAC National Accelerator Laboratory
Awards: G1229526393, G1285306620, G1286251239, G1847291448, G1867732070, G2004402655, G2371548206, G241279073, G262532246, G2849897711, G303061748, G3067052642, G315621713, G3262563802, G357145406, G3728080647, G4235786860, G495301720, G498139845, Pixel Array Detector for Macromolecular Crystallography, G5570207115, G5765906131, Trehalose-6-phosphate phosphatase inhibitors as anti-helminthics, Life Science and Biomedical technology Research center at NSLS-II LSBR, G6550344761, G6816383395, Trehalose-6-phosphate phosphatase: a target for anti-onchocerciasis therapeutics, G6965541988, G6985549539, G7283024673, G7463374569, G8382000481, G8701900045, A Synchrotron Radiation Structural Biology Resource, NE-CAT: A Resource for Advanced Macromolecular Crystallography, G911061179, G969889393
OpenAlex ID: W3046962793