RecBCD

RecBCD is an enzyme complex found in Escherichia coli (E. coli) and many other bacteria. The main function of RecBCD is to repair DNA that has been damaged. It does this by homologous recombination, a process that involves exchanging genetic information between two similar or identical strands of DNA.

Structure

RecBCD is made up of three subunits: RecB, RecC, and RecD. Each subunit plays a unique role in the function of the enzyme complex. RecB is a helicase and nuclease, RecC recognizes specific DNA sequences, and RecD is another helicase.

Function

The primary role of RecBCD is to repair double-strand breaks in DNA. These breaks can occur as a result of damage from ultraviolet light, radiation, or chemicals. RecBCD repairs these breaks through a process called homologous recombination.

In addition to its role in DNA repair, RecBCD also plays a role in the process of bacterial conjugation, which is a type of genetic recombination that involves the transfer of DNA from one bacterium to another.

Mechanism

The mechanism of RecBCD involves several steps. First, the enzyme binds to a double-strand break in the DNA. Then, it unwinds and separates the two strands of DNA. As it moves along the DNA, it degrades one strand while leaving the other intact. When it reaches a specific sequence of DNA known as a Chi site, it stops degrading the DNA and begins the process of recombination.

Clinical significance

Because of its role in DNA repair and recombination, RecBCD is of interest in the study of genetic diseases and cancer. Mutations in the genes that encode the RecBCD complex can lead to an increased risk of these conditions.

See also

• DNA repair
• Homologous recombination
• Bacterial conjugation

References

RecBCD Resources
Latest articles Most recent articles Ongoing trials	Wikipedia