https://repository.kopri.re.kr/handle/201206/5132 Sun, 12 Apr 2026 11:10:14 GMT 2026-04-12T11:10:14Z https://repository.kopri.re.kr/handle/201206/9434 Title: Crystal structure of dihydrodipicolinate reductase (PaDHDPR) from Paenisporosarcina sp. TG-14: structural basis for NADPH preference as a cofactor Authors: Lee, Chang Woo; Lee, Jun Hyuck; Park, Hyun; HaJeung Park; Hak Jun Kim; Hyun Ho Park; Lee, Sung Gu; Park, Sun-Ha Abstract: Dihydrodipicolinate reductase (DHDPR) is a key enzyme in the diaminopimelate- and lysine-synthesis pathways that reduces DHDP to tetrahydrodipicolinate. Although DHDPR uses both NADPH and NADH as a cofactor, the structural basis for cofactor specificity and preference remains unclear. Here, we report that Paenisporosarcina sp. TG-14 PaDHDPR has a strong preference for NADPH over NADH, as determined by isothermal titration calorimetry and enzymatic activity assays. We determined the crystal structures of PaDHDPR alone, with its competitive inhibitor (dipicolinate), and the ternary complex of the enzyme with dipicolinate and NADPH, with results showing that only the ternary complex had a fully closed conformation and suggesting that binding of both substrate and nucleotide cofactor is required for enzymatic activity. Moreover, NADPH binding induced local conformational changes in the N-terminal long loop (residues 34？59) of PaDHDPR, as the His35 and Lys36 residues in this loop interacted with the 2′-phosphate group of NADPH, possibly accounting for the strong preference of PaDHDPR for NADPH. Mutation of these residues revealed reduced NADPH binding and enzymatic activity, confirming their importance in NADPH binding. These findings provide insight into the mechanism of action and cofactor selectivity of this important bacterial enzyme. Mon, 01 Jan 2018 00:00:00 GMT https://repository.kopri.re.kr/handle/201206/9434 2018-01-01T00:00:00Z https://repository.kopri.re.kr/handle/201206/9129 Title: Studies on protein structure for the spore formation mechanism of microorganisms in polar glaciers Authors: Lee, Jun Hyuck Wed, 06 Dec 2017 00:00:00 GMT https://repository.kopri.re.kr/handle/201206/9129 2017-12-06T00:00:00Z https://repository.kopri.re.kr/handle/201206/5812 Title: Improving thermal hysteresis activity of antifreeze protein from recombinant Pichia pastoris by removal of N-glycosylation Authors: Kim, Eun Jae; Han, Se Jong; Lee, Sung Gu; Lee, Jun Hyuck Abstract: To survive in a sub-zero environment, polar organisms produce ice-binding proteins (IBPs). These IBPs prevent the formation of large intracellular ice crystals, which may be fatal to the organism. Recently, a recombinant FfIBP (an IBP from Flavobacterium frigoris PS1) was cloned and produced in Pichia pastoris using fed-batch fermentation with methanol feeding. In this study, we demonstrate that FfIBP produced by P. pastoris has a glycosylation site, which diminishes the TH activity of FfIBP. The FfIBP expressed by P. pastoris exhibited a doublet on SDS-PAGE. The results of a glycosidase reaction and PAS staining suggested that FfIBP possesses complex N-linked oligosaccharides. These results indicate that the residues of the glycosylated site could disturb the binding of FfIBP to ice molecules. The findings of this study could be utilized to produce highly active antifreeze proteins on a large scale. Sun, 01 Jan 2017 00:00:00 GMT https://repository.kopri.re.kr/handle/201206/5812 2017-01-01T00:00:00Z https://repository.kopri.re.kr/handle/201206/5823 Title: The genome of the Antarctic-endemic copepod,Tigriopus kingsejongensis Authors: Kang, Seunghyun; Park, Hyun; Kim, Sanghee; Kim, Hyun-Woo; Lee, Hyoungseok; Min, Gi-Sik; Lee, Jong Eun; Shin, Seung Chul; Lee, Sung Gu; Lee, Jun Hyuck; Ahn, Do Hwan Abstract: Background: The Antarctic intertidal zone is continuously subjected to extremely fluctuating biotic and abiotic stressors. The West Antarctic Peninsula is the most rapidly warming region on Earth. Organisms living in Antarctic intertidal pools are therefore interesting for research into evolutionary adaptation to extreme environments and the effects of climate change. Findings: We report the whole genome sequence of the Antarctic-endemic harpacticoid copepod Tigriopus kingsejongensi. The 37 Gb raw DNA sequence was generated using the Illumina Miseq platform. Libraries were prepared with 65-fold coverage and a total length of 295 Mb. The final assembly consists of 48 368 contigs with an N50 contig length of 17.5 kb, and 27 823 scaffolds with an N50 contig length of 159.2 kb. A total of 12 772 coding genes were inferred using the MAKER annotation pipeline. Comparative genome analysis revealed that T. kingsejongensis-specific genes are enriched in transport and metabolism processes. Furthermore, rapidly evolving genes related to energy metabolism showed positive selection signatures. Conclusions: The T. kingsejongensis genome provides an interesting example of an evolutionary strategy for Antarctic cold adaptation, and offers new genetic insights into Antarctic intertidal biota. Sun, 01 Jan 2017 00:00:00 GMT https://repository.kopri.re.kr/handle/201206/5823 2017-01-01T00:00:00Z