Folic acid utilisation related to sulfa drug resistance in Saccharomyces cerevisiae

Ann M Bayly, Janette M Berglez, Onisha Patel, Laura A Castelli, Eleanor G Hankins, Peter Coloe, Carol Hopkins Sibley, Ian Macreadie

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Saccharomyces cerevisiae mutants deficient in folate synthesis have been constructed and employed to study the utilisation of exogenous folates in yeast. One mutant specifically lacked dihydropteroate synthase while the second lacked dihydrofolate synthase. Exogenous folinic acid restored optimal growth to both strains. Folic acid did not generally rescue growth but spontaneous isolates capable of utilising folic acid were selected. The folic acid synthesis pathway in the folate utilising isolates was restored via transformation with FOL1 or FOL3 expression plasmids and transformants were tested for resistance to sulfamethoxazole (SMX). The presence of elevated levels of folic acid led to greatly reduced SMX sensitivity regardless of whether strains were folate utilisers or not.
Original languageEnglish
Pages (from-to)387 - 390
Number of pages4
JournalFEMS Microbiology Letters
Issue number2
Publication statusPublished - 2001

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Bayly, A. M., Berglez, J. M., Patel, O., Castelli, L. A., Hankins, E. G., Coloe, P., Sibley, C. H., & Macreadie, I. (2001). Folic acid utilisation related to sulfa drug resistance in Saccharomyces cerevisiae. FEMS Microbiology Letters, 204(2), 387 - 390.