comparative molecular modeling study of arabidopsis nadph-dependent thioredoxin reductase and its hybrid protein比较分子建模的研究拟南芥nadph-dependent硫氧还蛋白还原酶及其混合蛋白质.pdf

Comparative Molecular Modeling Study of Arabidopsis NADPH-Dependent Thioredoxin Reductase and Its Hybrid Protein Yuno Lee., Songmi Kim., Prettina Lazar, Jeong Chan Moon, Swan Hwang, Sundarapandian Thangapandian, Youngsik Shon, Kyun Oh Lee, Sang Yeol Lee, Keun Woo Lee* Division of Applied Life Science (BK21 Program), Systems and Synthetic Agrobiotech Center, Plant Molecular Biology and Biotechnology Research Center, Research Institute of Natural Science, Gyeongsang National University, Jinju, Gyeongsangnam-do, Republic of Korea Abstract 2-Cys peroxiredoxins (Prxs) play important roles in the protection of chloroplast proteins from oxidative damage. Arabidopsis NADPH-dependent thioredoxin reductase isotype C (AtNTRC) was identified as efficient electron donor for chloroplastic 2-Cys Prx-A. There are three isotypes (A, B, and C) of thioredoxin reductase (TrxR) in Arabidopsis. AtNTRA contains only TrxR domain, but AtNTRC consists of N-terminal TrxR and C-terminal thioredoxin (Trx) domains. AtNTRC has various oligomer structures, and Trx domain is important for chaperone activity. Our previous experimental study has reported that the hybrid protein (AtNTRA-(Trx-D)), which was a fusion of AtNTRA and Trx domain from AtNTRC, has formed variety of structures and shown strong chaperone activity. But, electron transfer mechanism was not detected at all. To find out the reason of this problem with structural basis, we performed two different molecular dynamics (MD) simulations on AtNTRC and AtNTRA-(Trx-D) proteins with same cofactors such as NADPH and flavin adenine dinucleotide (FAD) for 50 ns. Structural difference has found from superimposition of two structures that were taken relatively close to average structure. The main reason that AtNTRA-(Trx-D) cannot transfer the electron from TrxR domain t