Perturbations in the Heme and Siroheme Biosynthesis Pathways Causing Accumulation of Fluorescent Free Base Porphyrins and Auxotrophy in Ogataea Yeasts.
Azamat V KarginovAlexander A AlexandrovVitaly V KushnirovMichael O AgaphonovPublished in: Journal of fungi (Basel, Switzerland) (2021)
The biosynthesis of cyclic tetrapyrrol chromophores such as heme, siroheme, and chlorophyll involves the formation of fluorescent porphyrin precursors or compounds, which become fluorescent after oxidation. To identify Ogataea polymorpha mutations affecting the final steps of heme or siroheme biosynthesis, we performed a search for clones with fluorescence characteristic of free base porphyrins. One of the obtained mutants was defective in the gene encoding a homologue of Saccharomyces cerevisiae Met8 responsible for the last two steps of siroheme synthesis. Same as the originally obtained mutation, the targeted inactivation of this gene in O. polymorpha and O. parapolymorpha led to increased porphyrin fluorescence and methionine auxotrophy. These features allow the easy isolation of Met8-defective mutants and can potentially be used to construct auxotrophic strains in various yeast species. Besides MET8, this approach also identified the HEM3 gene encoding porphobilinogen deaminase, whose increased dosage led to free base porphyrin accumulation.
Keyphrases
- saccharomyces cerevisiae
- energy transfer
- quantum dots
- photodynamic therapy
- copy number
- living cells
- cell wall
- genome wide
- tyrosine kinase
- genome wide identification
- metal organic framework
- escherichia coli
- electron transfer
- label free
- gene expression
- hydrogen peroxide
- cancer therapy
- dna methylation
- transcription factor
- water soluble
- visible light