The Escherichia coli dihydrofolate reductase (DHFR) gene has been used as a genetic marker specifying trimethoprim resistance (TmpR). In order to use the DHFR gene as a versatile expression marker, we have constructed three types of plasmids: promoter cloning vector, terminator cloning vector, and the plasmid containing the DHFR gene cassette. In these systems, the selection of recombinant plasmids was carried out just by examining the TmpR phenotype of the transformed cells. Then, levels of the enzymatic activity of DHFR were measured to evaluate the efficiency of promoters and terminators in the fused DNA fragment. An expression plasmid which resulted in the E. coli host cells being able to produce DHFR up to 20% of total cellular proteins was also constructed by changing the promoter and Shine-Dalgarno sequences of the DHFR gene.
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http://dx.doi.org/10.1093/oxfordjournals.jbchem.a123714 | DOI Listing |
BMC Infect Dis
January 2025
Centre for Geographic Medicine Research (Coast), Kenya Medical Research Institute-Wellcome Trust Research Programme, Kilifi, Kenya.
Background: To understand the emergence and spread of drug-resistant parasites in malaria-endemic areas, accurate assessment and monitoring of antimalarial drug resistance markers is critical. Recent advances in next-generation sequencing (NGS) technologies have enabled the tracking of drug-resistant malaria parasites.
Methods: In this study, we used Targeted Amplicon Deep Sequencing (TADS) to characterise the genetic diversity of the Pfk13, Pfdhfr, Pfdhps, and Pfmdr1 genes among primary school-going children in 15 counties in Kenya (Bungoma, Busia, Homa Bay, Migori, Kakamega, Kilifi, Kirinyaga, Kisii, Kisumu, Kwale, Siaya, Tana River, Turkana, Vihiga and West Pokot).
Nutrients
December 2024
Departments of Human Genetics and Pediatrics, McGill University, Montreal, QC H3A 0C7, Canada.
Background/objectives: The gene variant results in a thermolabile MTHFR enzyme associated with elevated plasma homocysteine in TT individuals. Health risks associated with the TT genotype may be modified by dietary and supplemental folate intake. Supplementation with methyltetrahydrofolate (methylTHF) may be preferable to folic acid because it is the MTHFR product, and does not require reduction by DHFR to enter one-carbon folate metabolism.
View Article and Find Full Text PDFInfect Drug Resist
December 2024
Beijing Institute of Tropical Medicine, Beijing Friendship Hospital, Capital Medical University, Beijing, People's Republic of China.
Purpose: pneumonia (PJP) shows a high fatality rate in non-HIV patients. However, there are limited data on drug resistance-related gene mutations in these patients. This study aimed to describe the prevalence of mutations in the dihydrofolate reductase (DHFR) and dihydropteroate synthase (DHPS) genes of in non-HIV patients in China, providing a reference for drug usage.
View Article and Find Full Text PDFStructure
December 2024
Department of Biology, University of Copenhagen, Ole Maaløes Vej 5, 2200 Copenhagen, Denmark. Electronic address:
Gene variants resulting in insertions or deletions of amino acid residues (indels) have important consequences for evolution and are often linked to disease, yet, compared to missense variants, the effects of indels are poorly understood and predicted. We developed a sensitive protein folding sensor based on the complementation of uracil auxotrophy in yeast by circular permutated orotate phosphoribosyltransferase (CPOP). The sensor reports on the folding of disease-linked missense variants and de-novo-designed proteins.
View Article and Find Full Text PDFWellcome Open Res
June 2024
MARCAD Program, The biotechnology Centre, University of Yaounde I, Yaounde, Centre, P 0 Box 8094, Cameroon.
Background: Antimalarial drug resistance is a major challenge in the fight against malaria. Cameroon implemented seasonal malaria chemoprevention (SMC) with sulfadoxine-pyrimethamine and amodiaquine (SPAQ) to over 1.5 million children aged 3-59 months from 2016, raising concerns whether drug pressure may lead to a selection of known parasite resistance mutations.
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