New regulatory mechanism of intracellular antioxidative system by the yeast acetyltransferase Mpr1

2015 Fiscal Year Final Research Report

• Project/Area Number: 25660058
• Research Category: Grant-in-Aid for Challenging Exploratory Research
• Allocation Type: Multi-year Fund
• Research Field: Applied microbiology
• Research Institution: Nara Institute of Science and Technology
• Principal Investigator: Takagi Hiroshi 奈良先端科学技術大学院大学, バイオサイエンス研究科, 教授 (50275088)
• Co-Investigator(Renkei-kenkyūsha): OHTSU Iwao 奈良先端科学技術大学院大学, バイオサイエンス研究科, 助教 (60395655)
• Research Collaborator: NASUNO Ryo
• Project Period (FY): 2013-04-01 – 2016-03-31
• Keywords: N-アセチルトランスフェラーゼMpr1 / 酵母 / アルギニン合成 / プロリン代謝 / 酸化ストレス耐性

Outline of Final Research Achievements

We constructed stable Mpr1 variants by a rational design based on its crystal structure. Substitution of Asn203 to a Lys was suggested to stabilize α-helix 2, which is important for the whole structure of Mpr1, probably by neutralizing its dipole moment, leading to an increase in the thermostability of Mpr1. Expression of the Mpr1 variant enhanced the arginine biosynthesis in yeast. This finding will lead to the construction of new yeast strains with increased arginine synthetic activity and fermentation rate. We also attempted to clarify the Mpr1-dependent arginine synthetic pathway in yeast including identification of the cellular substrate of Mpr1 and its catalytic reaction. As a result, N-acetyl proline, which is converted from proline catalyzed by Mpr1, was suggested to function as the intermediate for Mpr1-dependent ariginine synthesis or the regulator for the arginine metabolic enzyme.

Free Research Field

応用微生物学