Novel Cysteine-Centered Sulfur Metabolic Pathway in the Thermotolerant Methylotrophic Yeast Hansenula polymorpha
Novel Cysteine-Centered Sulfur Metabolic Pathway in the Thermotolerant Methylotrophic Yeast Hansenula polymorpha
复制标题
耐热甲基营养酵母汉逊酵母中新的以半胱氨酸为中心的硫代谢途径
作者：
M. Sohn;S. Yoo;D. Oh;O. Kwon;S. Lee;A. Sibirny;H. Kang
在酵母和丝状真菌中，硫化物可以与O-乙酰高丝氨酸缩合生成同型半胱氨酸，蛋氨酸的前体，或与O-乙酰丝氨酸缩合直接生成半胱氨酸。同型半胱氨酸和半胱氨酸可以通过转硫途径相互转化。在这里，我们系统地分析了硫代谢途径的耐热甲基营养型酵母Hansenula polymorpha，这引起了人们的关注，作为一个工业酵母菌株的各种生物技术应用。非常有趣的是，详细的硫代谢途径H。基于基因组序列的组合分析和通过系统的基因缺失实验的验证而重建的polymorpha揭示了在该酵母中不存在从无机硫从头合成高半胱氨酸。因此，从硫化物直接生物合成半胱氨酸是从H.此外，只有半胱氨酸，而不是其他含硫氨基酸，能够抑制硫基因的一个子集的表达，这表明它在控制H.硫代谢35 S-Cys在H.多形，进一步支持以半胱氨酸为中心的硫途径。这是首次报道H. polymorpha硫代谢途径，这与其他酵母和丝状真菌物种的硫代谢途径明显不同。
In yeast and filamentous fungi, sulfide can be condensed either with O-acetylhomoserine to generate homocysteine, the precursor of methionine, or with O-acetylserine to directly generate cysteine. The resulting homocysteine and cysteine can be interconverted through transsulfuration pathway. Here, we systematically analyzed the sulfur metabolic pathway of the thermotolerant methylotrophic yeast Hansenula polymorpha, which has attracted much attention as an industrial yeast strain for various biotechnological applications. Quite interestingly, the detailed sulfur metabolic pathway of H. polymorpha, which was reconstructed based on combined analyses of the genome sequences and validation by systematic gene deletion experiments, revealed the absence of de novo synthesis of homocysteine from inorganic sulfur in this yeast. Thus, the direct biosynthesis of cysteine from sulfide is the only pathway of synthesizing sulfur amino acids from inorganic sulfur in H. polymorpha, despite the presence of both directions of transsulfuration pathway Moreover, only cysteine, but no other sulfur amino acid, was able to repress the expression of a subset of sulfur genes, suggesting its central and exclusive role in the control of H. polymorpha sulfur metabolism. 35S-Cys was more efficiently incorporated into intracellular sulfur compounds such as glutathione than 35S-Met in H. polymorpha, further supporting the cysteine-centered sulfur pathway. This is the first report on the novel features of H. polymorpha sulfur metabolic pathway, which are noticeably distinct from those of other yeast and filamentous fungal species.
高效液相色谱法测定蛋白质-谷胱甘肽混合二硫化物。
影响因子：
2.9
作者：
Kumari,K;Khanna,P;Ansari,NH;Srivastava,SK
通讯作者：
Srivastava,SK