l-Cysteine Metabolism Found in Saccharomyces cerevisiae and Ogataea parapolymorpha
Sulfur’s cellular requirements can be met by the cell’s uptake of sulfur-containing amino acids. The requirements can also be fulfilled by the cell’s assimilation of inorganic sulfur into organic compounds, such as l-homocysteine (Hcy) and l-cysteine (Cys), which are used for the biosynthesis of l-methionine (Met) and l-glutathione (GSH), respectively. Cys can be synthesized via the sulfur assimilation pathway in microorganisms and plants, but not the corresponding pathway in animals. Saccharomyces cerevisiae, which is the conventional yeast, synthesizes Cys from Hcy via a reverse trans-sulfuration pathway. It has been concluded that Cys is synthesized exclusively by l-cystathionine β-synthase and l-cystathionine γ-lyase. A promising host strain for high-level production of GSH is the thermotolerant methylotrophic yeast Ogataea parapolymorpha (formerly Hansenula polymorpha). Domain analyses of the serine O-acetyltransferase (SAT) in the non-conventional yeast Ogataea parapolymorpha (OpSat1) and those of other fungal SATs have demonstrated that these proteins have a mitochondrial targeting sequence (MTS) at the N-terminus that differs markedly from the classical bacterial and plant SATs. OpSat1 is functionally interchangeable with the E. coli SAT, i.e., CysE, even though compared to CysE, OpSat1 has far lower enzymatic activity, with marginal feedback inhibition by Cys. In light of the key role of OpSat1 in the regulation of the pathway of Cys biosynthesis in O. parapolymorpha, and its crucial role in sulfur metabolism, it is apparent that OpSat1 could be a target for the metabolic engineering used to generate yeast strains that produce sulfur-containing metabolites such as GSH.
Keywordsl-Cysteine Sulfur Sulfate Thiosulfate Saccharomyces cerevisiae Ogataea parapolymorpha O-Acetyl-l-serine l-Serine O-Acetyltransferase Feedback inhibition Mitochondria
We are greatly indebted to our co-researchers Dr. Hyun Ah Kang, Ji Yoon Yeon, and Su Jin Yoo (Chung-Ang University, Seoul, Korea) and Dr. Bun-ichiro Ono (Ritsumeikan University, Japan). I am also grateful to Dr. Shigeru Nakamori (Fukui Prefectural University, Fukui, Japan) and Dr. Iwao Ohtsu (Nara Institute Science and Technology, Nara, Japan). This review includes the work supported by a grant from Ajinomoto, Co., Inc., to H.T.
- Funahashi E, Saiki K, Honda K, Sugiura Y, Kawano Y, Ohtsu I, Watanabe D, Wakabayashi Y, Abe T, Nakanishi T, Suematsu M, Takagi H (2015) A finding of thiosulfate pathway for synthesis of organic sulfur compounds in Saccharomyces cerevisiae and an improvement of ethanol production. J Biosci Bioeng 120:666–669CrossRefGoogle Scholar
- Hunt S (1985) Degradation of amino acids accompanying in vitro protein hydrolysis. In: Barrett GC (ed) Chemistry and biology of the amino acids. Chapman & Hall, London, pp 3763–3798Google Scholar
- Kai Y, Kashiwagi T, Ishikawa K, Ziyatdinov MK, Redkina EI, Kiriukhin MY, Gusyatiner MM, Kobayashi S, Takagi H, Suzuki E (2006) Engineering of Escherichia coli l-serine O-acetyltransferase on the basis of crystal structure: desensitization to feedback inhibition by l-cysteine. Protein Eng Des Sel 19:163–167CrossRefGoogle Scholar
- Kaszycki P, Walski T, Hachicho N, Heipieper HJ (2013) Biostimulation by methanol enables the methylotrophic yeasts Hansenula polymorpha and Trichosporon sp. to reveal high formaldehyde biodegradation potential as well as to adapt to this toxic pollutant. Appl Microbiol Biotechnol 97:5555–5564CrossRefGoogle Scholar
- Kredich NM (1996) Biosynthesis of cysteine. In: Neidhardt FC, Curtiss RIII, Ingraham JL, Lin ECC, Low KB, Magasanik B, Reznicoff WS, Riley M, Schaechter M, Umbarger JE (eds) Escherichia coli and Salmonella typhimurium: cellular and molecular biology, 2nd edn. ASM, Washington, DC, pp 514–527Google Scholar
- Nakatani T, Ohtsu I, Nonaka G, Wiriyathanawudhiwong N, Morigasaki S, Takagi H (2012) Enhancement of thioredoxin/glutaredoxin-mediated l-cysteine synthesis from S-sulfocysteine increases l-cysteine production in Escherichia coli. Microb Cell Factories 11:62. https://doi.org/10.1186/1475-2859-11-62CrossRefGoogle Scholar
- Soda K (1987) Microbial sulfur amino acids: an overview. In: Jakoby WB, Griffith OW (eds) Methods in enzymology, vol 143. Academic Press, Orlando, pp 453–459Google Scholar
- Takagi H, Kobayashi C, Kobayashi S, Nakamori S (1999a) PCR random mutagenesis into Escherichia coli serine acetyltransferase: isolation of the mutant enzymes that cause overproduction of l-cysteine and l-cystine due to the desensitization to feedback inhibition. FEBS Lett 452:323–327CrossRefGoogle Scholar
- Vermeji P, Kertesz MA (1999) Pathways of assimilative sulfur metabolism in Pseudomonas putida. J Bacteriol 181:5833–5837Google Scholar