DNA-binding protein from starved cells

DPS 1qgh

DNA-binding protein from starved cells (Dps) is a protein that plays a crucial role in the survival of bacteria under stressful conditions, particularly during starvation. Dps is a member of the ferritin superfamily and is known for its ability to protect DNA from oxidative damage and other environmental stresses.

Structure

Dps proteins typically form a dodecameric structure, consisting of 12 identical subunits. This structure allows Dps to bind and protect DNA efficiently. The protein has a hollow core where it can sequester iron, thus preventing the formation of harmful reactive oxygen species (ROS) through the Fenton reaction.

Function

The primary function of Dps is to protect bacterial DNA during periods of nutrient deprivation and other stress conditions. It achieves this by binding to DNA and shielding it from oxidative damage. Additionally, Dps can store iron within its core, reducing the availability of free iron that could catalyze the formation of ROS.

DNA Protection

Dps binds to DNA in a non-specific manner, forming a protective coat around the DNA molecule. This binding helps to prevent DNA strand breaks and other forms of damage caused by oxidative stress.

Iron Sequestration

By sequestering iron, Dps reduces the potential for oxidative damage. Iron is a critical element for many cellular processes, but its free form can participate in reactions that generate ROS. Dps helps to mitigate this risk by storing iron safely within its structure.

Regulation

The expression of Dps is tightly regulated and is typically induced under conditions of starvation, oxidative stress, and during the stationary phase of bacterial growth. Regulatory proteins and environmental signals play a role in modulating the levels of Dps within the cell.

Importance in Bacterial Survival

Dps is essential for the survival of many bacteria under adverse conditions. Its ability to protect DNA and manage iron homeostasis makes it a key player in the bacterial stress response. This protein is particularly important for pathogenic bacteria, which often encounter hostile environments within their hosts.

Related Pages

• DNA
• Ferritin
• Reactive oxygen species
• Oxidative stress
• Starvation
• Bacterial stress response