Loading…
Hypoxanthine-Guanine Phosphoribosyltransferase Is Dispensable for Mycobacterium smegmatis Viability
Purine metabolism plays a ubiquitous role in the physiology of and other mycobacteria. The purine salvage enzyme hypoxanthine-guanine phosphoribosyltransferase (HGPRT) is essential for growth ; however, its precise role in physiology is unclear. Membrane-permeable prodrugs of specifically designed H...
Saved in:
Published in: | Journal of bacteriology 2020-02, Vol.202 (5) |
---|---|
Main Authors: | , , , |
Format: | Article |
Language: | English |
Subjects: | |
Citations: | Items that this one cites Items that cite this one |
Online Access: | Get full text |
Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
Summary: | Purine metabolism plays a ubiquitous role in the physiology of
and other mycobacteria. The purine salvage enzyme hypoxanthine-guanine phosphoribosyltransferase (HGPRT) is essential for
growth
; however, its precise role in
physiology is unclear. Membrane-permeable prodrugs of specifically designed HGPRT inhibitors arrest the growth of
and represent potential new antituberculosis compounds. Here, we investigated the purine salvage pathway in the model organism
Using genomic deletion analysis, we confirmed that HGPRT is the only guanine and hypoxanthine salvage enzyme in
but is not required for
growth of this mycobacterium or survival under long-term stationary-phase conditions. We also found that prodrugs of
HGPRT inhibitors displayed an unexpected antimicrobial activity against
that is independent of HGPRT. Our data point to a different mode of mechanism of action for these inhibitors than was originally proposed.
Purine bases, released by the hydrolytic and phosphorolytic degradation of nucleic acids and nucleotides, can be salvaged and recycled. The hypoxanthine-guanine phosphoribosyltransferase (HGPRT), which catalyzes the formation of guanosine-5'-monophosphate from guanine and inosine-5'-monophosphate from hypoxanthine, represents a potential target for specific inhibitor development. Deletion of the HGPRT gene (
) in the model organism
confirmed that this enzyme is not essential for
growth. Prodrugs of acyclic nucleoside phosphonates (ANPs), originally designed against HGPRT from
, displayed anti-
activities comparable to those obtained for
but also inhibited the
strain. These results confirmed that ANPs act in
by a mechanism independent of HGPRT. |
---|---|
ISSN: | 0021-9193 1098-5530 |
DOI: | 10.1128/JB.00710-19 |