Fep1, the iron-responsive GATA factor from the methylotrophic yeast Pichia pastoris, has been characterised both in vivo and in vitro. This protein has two Cys2-Cys2 type zinc fingers and a set of four conserved cysteines arranged in a Cys-X5-Cys-X8-Cys-X2-Cys motif located between the two zinc fingers. Electronic absorption and resonance Raman spectroscopic analyses in anaerobic and aerobic conditions indicate that Fep1 binds iron in the form of a [2Fe-2S] cluster. Site-directed mutagenesis shows that replacement of the four cysteines with serine inactivates this transcriptional repressor. Unexpectedly, the inactive mutant is still able to bind a [2Fe-2S] cluster, employing two cysteine residues belonging to the first zinc finger. These two cysteine residues can act as alternative cluster ligands selectively in aerobically purified Fep1 wild type, suggesting that oxygen could play a role in Fep1 function by causing differential localization of the [Fe-S] cluster.
Download full-text PDF |
Source |
---|---|
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4992955 | PMC |
http://dx.doi.org/10.1038/srep31872 | DOI Listing |
Microorganisms
December 2024
Department of Chemical, Biological and Environmental Engineering, Universitat Autònoma de Barcelona, Carrer de les Sitges, s/n, 08193 Bellaterra, Catalonia, Spain.
The introduction of heterologous pathways into microbial cell compartments offers several potential advantages, including increasing enzyme concentrations and reducing competition with native pathways, making this approach attractive for producing complex metabolites like fatty acids and fatty alcohols. However, measuring subcellular concentrations of these metabolites remains technically challenging. Here, we explored 3-hydroxypropionic acid (3-HP), readily quantifiable and sharing the same precursors-acetyl-CoA, NADPH, and ATP-with the above-mentioned products, as a reporter metabolite for peroxisomal engineering in the yeast .
View Article and Find Full Text PDFSheng Wu Gong Cheng Xue Bao
January 2025
Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing 100193, China.
Glucose oxidase (GOD) is an oxygen-consuming dehydrogenase that can catalyze the production of gluconic acid hydrogen peroxide from glucose, and its specific mechanism of action makes it promising for applications, while the low catalytic activity and poor thermostability have become the main factors limiting the industrial application of this enzyme. In this study, we used the glucose oxidase GOD reported with the best thermostability as the source sequence for phylogenetic analysis to obtain the GOD with excellent performance. Six genes were screened and successfully synthesized for functional validation.
View Article and Find Full Text PDFJ Biol Chem
January 2025
Department of Biochemistry, Indian Institute of Science, Bangalore 560012, INDIA. Electronic address:
The zinc finger transcription factor Mxr1 (methanol expression regulator 1) of the methylotrophic yeast Komagataella phaffii (formerly Pichia pastoris) harbors a DNA-binding domain (DBD) consisting of two CH zinc fingers (Mxr1ZF) between amino acids 36-101 and a previously identified nine amino acid transactivation domain (9aaTAD) between residues 365-373 (TAD A, QELESSLNA). Beyond this, 21 putative 9aaTADs (designated TAD B-V) located between amino acids 401-1155 remain to be characterized. Here, we demonstrate that a compact synthetic transcription factor composed of Mxr1ZF and three tandem copies of TAD A can activate the transcription of Mxr1 target genes for ethanol and methanol metabolism with specificity and efficiency comparable to the full-length protein.
View Article and Find Full Text PDFJ Environ Manage
January 2025
College of Bioscience and Biotechnology, Shenyang Agricultural University, Shenyang, 110866, China. Electronic address:
Polybutylene succinate (PBS), a biodegradable plastic, can be used as an alternative to traditional plastics to effectively solve the growing plastic pollution. Although PBS is theoretically completely biodegradable, slow degradation remains a problem in practical applications, leading to the possibility of environmental pollution. In this study, after the PBS degradation ability of the fungus Paraphoma chrysanthemicola was determined, a P.
View Article and Find Full Text PDFBioengineering (Basel)
January 2025
AgResearch Ltd., Grasslands, Palmerston North 4442, New Zealand.
Enzymatic depolymerisation is increasingly recognised as a reliable and environmentally friendly method. The development of this technology hinges on the availability of high-quality enzymes and associated bioreaction systems for upscaling biodegradation. Microbial heterologous expression systems have been studied for meeting this demand.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!