Credit: ORNL/Jill Hemman |
Water plays several important roles within the human body, even affecting the DNA in our cells. The entire surface of a DNA double helix is coated in layers of water molecules. This sheath of water attaches to the genetic material through hydrogen bonds, made by sharing hydrogen atoms between molecules. Through hydrogen bonds, water can influence how DNA takes shape and interacts with other molecules. In some cases, water can help proteins recognize DNA sequences.
Scientists can estimate where hydrogen bonds occur and how hydrogen atoms are shared, but it is difficult to gather experimental evidence. A research team led by Vanderbilt University has used a method that successfully captured the most detailed view to date of water’s hydrogen bonding patterns around DNA, opening new possibilities for studying how water impacts DNA function. Details on the methodology and the results, produced in part through neutron scattering at the Department of Energy’s (DOE’s) Oak Ridge National Laboratory (ORNL), are published in the journal Nucleic Acids Research.
“Water serves as a mediator between DNA and other molecules, even for very specific interactions. Before any molecule can bind to a segment of DNA, it must first go through this water shell,” said Martin Egli, a biochemistry professor at Vanderbilt University and corresponding author of the study. “To advance our understanding of DNA processes, it’s important to know exactly what the surrounding water does and how it arranges itself around molecules.”