Improvement of metal ions acquisition ability of Dps protein from Klebsiella oxytoca

• Main Authors: Chung-Wei Lin, 林均蔚
• Other Authors: 劉俊宏
• Format: Others
• Language: zh-TW
• Published: 2015
• Online Access: http://ndltd.ncl.edu.tw/handle/14353502238234888433

碩士 === 國立中興大學 === 基因體暨生物資訊學研究所 === 103 === Dps (DNA-binding protein from starved cells) was found in prokaryots. Hosts express Dps to protect itself from oxidative stress condition and keep cells alive. The oxidative protection is achieved in two ways: (1) Dps binds Fe2+ ions and prevents the Fenton reaction formation of free radicals. (2) Dps binds DNA and shields it from oxidative damage. In this study, we tried to improve the metal ions acquisition ability of Dps. We chose Klebsiella oxytoca Dps (KoDps) as a target. KoDps was genetically modified by adding 1~3 repeats of glycine-glutamic acid-aspartic acid on N-terminus and 1~3 repeats of glycine-glutamic acid-aspartic glycine on C-terminus, and measured the metal ions acquisition ability by tryptophan fluorescent quenching assays. The results showed that some of these mutants had improved metal ions acquisition ability. Detailed structural information on KoDps is needed to understand the mechanism of metal ions uptake pathway, therefore we tried to solve the structure of KoDps. We have found some crystal conditions of KoDps, but the crystal structure has not resolved yet. Finally, we predicted the structure of KoDps and compared with Escherichia coli Dps (EcDp). These results will help us to understand the mechanism of metal ions uptake pathway of Dps.