Polyamines produced by an extreme thermophile are essential for cell growth at high temperature

• Published in: Journal of biochemistry (Tokyo) 2022-08, Vol.172 (2), p.109-115
• Main Authors: Sakamoto, Akihiko, Tamakoshi, Masatada, Moriya, Toshiyuki, Oshima, Tairo, Takao, Koichi, Sugita, Yoshiaki, Furuchi, Takemitsu, Niitsu, Masaru, Uemura, Takeshi, Igarashi, Kazuei, Kashiwagi, Keiko, Terui, Yusuke
• Format: Article
• Language: English
• ISSN: 0021-924X; 1756-2651
• DOI: 10.1093/jb/mvac048

Abstract An extreme thermophile, Thermus thermophilus grows at an optimum temperature of around 70°C and produces 16 different polyamines including long-chain and branched-chain polyamines. We found that the composition of polyamines in the thermophile cells changes with culture temperature. Long-chain and branched-chain polyamines (unusual polyamines) were increased in the cells grown at high temperature such as 80°C, but they were minor components in the cells grown at relatively lower temperature such as 60°C. The effects of polyamines on cell growth were studied using T. thermophilus HB8 ΔspeA deficient in arginine decarboxylase. Cell growth of this mutant strain was significantly decreased at 70°C. This mutant strain cannot produce polyamines and grows poorly at 75°C. It was also determined whether polyamines are directly involved in protecting DNA from DNA double-strand breaks (DSBs) induced by heat. Polyamines protected DNA against double-strand breaks. Therefore, polyamines play essential roles in cell growth at extremely high temperature through maintaining a functional conformation of DNA against DSBs and depurination. Graphical Abstract Graphical Abstract