Serang Bong1,†, Chung Bin Park1,†, Shin-Gyu Cho2,†, Jaeyoung Bae1,†, Natalia Diyah Hapsari1,3,†, Xuelin Jin1,4,†, Sujung Heo1, Ji-eun Lee2, Kaori Hashiya5, Toshikazu Bando5, Hiroshi Sugiyama 5, Kwang-Hwan Jung 2,*, Bong June Sung1,* and Kyubong Jo1,*
1Department of Chemistry, Sogang University, Seoul 04107, Korea,
2Department of Life Science, Sogang University, Seoul 04107, Korea,
3Chemistry Education Program, Department of Mathematics and Science Education, Sanata Dharma University, Yogyakarta 55282, Indonesia,
4College of Agriculture, Yanbian University, Yanji133000, China
5Department of Chemistry, Graduate School of Science, Kyoto University, Sakyo-Ku, Kyoto606-8502, Japan
†The authors wish it to be known that, in their opinion, the first six authors should be regarded as Joint First Authors.
*Correspondence : Kwang-Hwan Jung, Bong June Sung, Kyubong Jo
In this study, we specifically visualized DNA molecules at their AT base pairs after in vitro phage ejection. Our AT-specific visualization revealed that either end of the DNA molecule could be ejected first with a nearly 50% probability. This observation challenges the generally accepted theory of Last In First Out (LIFO), which states that the end of the phage λ DNA that enters the capsid last during phage packaging is the first to be ejected, and that both ends of the DNA are unable to move within the extremely condensed phage capsid. To support our observations, we conducted computer simulations that revealed that both ends of the DNA molecule are randomized, resulting in the observed near 50% probability. Additionally, we found that the length of the ejected DNA by LIFO was consistently longer than that by First In First Out (FIFO) during in vitro phage ejection. Our simulations attributed this difference in length to the stiffness difference of the remaining DNA within the phage capsid. In conclusion, this study demonstrates that a DNA molecule within an extremely dense phage capsid exhibits a degree of mobility, allowing it to switch ends during ejection.