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Temperature-dependent DNA binding of DicA protein in vivo and in vitro
Korean J. Microbiol 2019;55(3):181-190
Published online September 30, 2019
© 2019 The Microbiological Society of Korea.

Yonho Lee1, Sang Hoon Yun2, and Heon M. Lim1*

1Department of Biological Sciences, College of Biological Sciences and Biotechnology, Chungnam National University, Daejeon 34134, Republic of Korea
2Alteogen, Daejeon 34054, Republic of Korea
Correspondence to: *E-mail: hmlim@cnu.ac.kr; Tel.: +82-42-821-6276; Fax: +82-42-822-9690
Received February 27, 2019; Revised June 15, 2019; Accepted June 26, 2019.
Abstract
In Escherichia coli, DicA protein is involved in cell division control. DicA protein is known to bind DNA better at 25°C than at 37°C. However, the molecular cause of the temperature dependent binding is not clear. In this study, we investigated how DicA binds DNA and why its DNA binding activity depends on temperature. An unique in vivo DNA binding assay developed in this laboratory showed that unlike the homologous proteins such as RovA or SlyA, DicA uses its N-terminal domain for DNA binding. The in vivo DNA binding assay of DicA also demonstrated that the temperature-dependent DNA binding activity does not come from Cnu or H-NS that is known to bind DNA better at 25°C than at 37°C. Electrophoretic Mobility Shift Assay (EMSA), when performed with purified DicA protein, did not show temperature-dependent DicA binding activity. However when EMSA was performed with crude protein from WT E. coli cells, temperature-dependent DicA binding activity was observed, suggesting that there is a factor(s) that confers temperature DNA binding activity of DicA in vivo.
Keywords : Escherichia coli, DicA, DNA binding, filamentous growth, temperature-dependent DNA binding activity


September 2019, 55 (3)