121st General Meeting of the KCS

Type Poster Presentation
Area Life Chemistry
Room No. Event Hall
Time 4월 20일 (금요일) 11:00~12:30
Code BIO.P-286
Subject The Zα-induced B-to-Z conversion rate is kinetically accelerated by introducing single-stranded regions
Authors Ji-Ye Yun, Seul Ki Lee, Hyuk Won, Yang-Gyun Kim1,*
Chemistry, Sungkyunkwan University, Korea
1Department of Chemistry, Sungkyunkwan University, Korea
Abstract Z-DNA is a left-handed duplex DNA that contains a zigzag backbone. Since the first crystal structure of Z-DNA was revealed, there have been many studies about chemical and physical characteristics of the left-handed DNA. Z-DNA formation is favored under specific circumstances such as high energy state, high salt and base modifications. Biological meaning of Z-DNA has been suggested by the identification of Z-DNA binding proteins. Z-DNA binding motif, Zα, was first discovered from ADAR1 and also was known to exist in families of proteins. Once the B-DNA is inverted into a Z-DNA conformation, the Zα domain from human ADAR protein (ZαADAR1) is bound to the DNA and prevents its returning to the B conformation. In this study, the effect of unpaired region of DNA such as overhangs and hairpin on the B-Z transition by ZαADAR1 was examined. We used double-stranded d(CG)6 core with 5’ or 3’ overhang, which are 1 to 6 nucleotide-long with either A or T. The result shows that overhang DNAs were more rapidly converted non-overhang ds-DNA. Especially, the B-to-Z conversion of ds-d(CG)6-T series DNAs depended on the length of the overhang region. Considering these findings, we extended the investigation on the kinetic behaviors of the B-to-Z conversion of hairpin-DNAs. The result reveals the rate of the B-to-Z conversion was also loop-length dependent. Moreover, we conducted double-stranded RNA substrates to see the effect of overhang region on B-to-Z conversion. The result confirmed that dsRNA with an overhang was also converted faster than non-overhang ds-RNA. Collectively, Zα stimulates the formation of Z-conformer in nucleic acids in the presence of single-stranded region, which may play some roles in B-to-Z conversion events in vivo.
E-mail jiye120@naver.com