https://repository.kopri.re.kr/handle/201206/5377 2026-04-07T05:39:56Z https://repository.kopri.re.kr/handle/201206/5680 Title: Characterization of Cold-Shock Protein A of Antarctic Streptomyces sp. AA8321 Authors: Lee, Yoo Kyung; Kim, Min-Jung; Lee, Hong Kum; Im, Hana Abstract: Polar organisms should have mechanisms to survive the extremely cold environment. Four genes encoding cold-shock proteins, which are small, cold-induced bacterial proteins, have been cloned from the Antarctic bacterium Streptomyces sp. AA8321. Since the specific functions of any polar bacterial or Streptomyces cold-shock proteins have not yet been determined, we examined the role of cold-shock protein A from Streptomyces sp. AA8321 (CspASt). Gel filtration chromatography showed that purified CspASt exists as a homodimer under physiological conditions, and gel shift assays showed that it binds to single-stranded, but not double-stranded, DNA. Overexpression of CspASt in Escherichia coli severely impaired the ability of the host cells to form colonies, and the cells developed an elongated morphology. Incorporation of a deoxynucleoside analogue, 5-bromo-2？-deoxyuridine, into newly synthesized DNA was also drastically diminished in CspASt-overexpressing cells. These results suggest that CspASt play a role in inhibition of DNA replication during cold-adaptation. 2007-01-01T00:00:00Z https://repository.kopri.re.kr/handle/201206/5940 Title: Characterization of the gene for the light-harvesting peridinin-chlorophyll-protein of Alexandrium tamarense Authors: Lee, S.Y.; Kang, Sung-Ho; Jin, EonSeon Abstract: Photosynthetic dinoflagellates contain a water-soluble, light-harvesting antenna called the peridinin-chlorophyll-protein (PCP) complex, which has an apoprotein with no sequence similarity to other known proteins. There are two forms of PCP apoproteins;the 15-kDa short form and the 32- to 35-kDa long form. The present study describes the PCP protein and its cDNA from Alexandrium tamarense. A cDNA library was constructed from mRNA isolated from A. tamarense. The complete PCP cDNA was generated by reverse-transcription coupled to polymerase chain reaction (RT-PCR), together with rapid-amplification of cDNA ends (RACE). The A. tamarense PCP cDNA encoded a 55-amino acid signal peptide and a 313-amino acid mature protein with a calculated mass of 32 kDa, which corresponded to that of the long form of PCP. Phylogenetic analysis indicated that the sequence of A. tamarense PCP did not cluster with the short-form PCPs, to which it was only about 55% identical, but which were 79-83% identical to other long-form PCPs. The deduced amino acid sequence of A. tamarense PCP contains an internal duplication, which suggests the possibility that long-form PCPs arose by gene duplication or by the fusion of genes encoding the short form. The abundance of PCP mRNA changed substantially in response to different light conditions, indicating the possible existence of a photo-acclimation response in A. tamarense. 2005-01-01T00:00:00Z https://repository.kopri.re.kr/handle/201206/7587 Title: Polar microalgal analysis for natural product Authors: 권태연; 하태열; Kang, Sung-Ho Abstract: 극지미세조류의 유용성분 함량과 항산화 활성 2005-01-01T00:00:00Z