The Bateman domain of IMP dehydrogenase is a binding target for dinucleoside polyphosphates.
J Biol Chem
; 294(40): 14768-14775, 2019 10 04.
Article
in En
| MEDLINE
| ID: mdl-31416831
ABSTRACT
IMP dehydrogenase (IMPDH) is an essential enzyme that catalyzes the rate-limiting step in the de novo guanine nucleotide biosynthetic pathway. Because of its involvement in the control of cell division and proliferation, IMPDH represents a therapeutic for managing several diseases, including microbial infections and cancer. IMPDH must be tightly regulated, but the molecular mechanisms responsible for its physiological regulation remain unknown. To this end, we recently reported an important role of adenine and guanine mononucleotides that bind to the regulatory Bateman domain to allosterically modulate the catalytic activity of eukaryotic IMPDHs. Here, we have used enzyme kinetics, X-ray crystallography, and small-angle X-ray scattering (SAXS) methodologies to demonstrate that adenine/guanine dinucleoside polyphosphates bind to the Bateman domain of IMPDH from the fungus Ashbya gossypii with submicromolar affinities. We found that these dinucleoside polyphosphates modulate the catalytic activity of IMPDHs in vitro by efficiently competing with the adenine/guanine mononucleotides for the allosteric sites. These results suggest that dinucleoside polyphosphates play important physiological roles in the allosteric regulation of IMPDHs by adding an additional mechanism for fine-tuning the activities of these enzymes. We propose that these findings may have important implications for the design of therapeutic strategies to inhibit IMPDHs.
Key words
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Protein Conformation
/
Dinucleoside Phosphates
/
Protein Domains
/
IMP Dehydrogenase
Type of study:
Prognostic_studies
Limits:
Humans
Language:
En
Journal:
J Biol Chem
Year:
2019
Document type:
Article
Affiliation country:
Spain