MRE11A

Double-strand break repair protein MRE11A is a protein that in humans is encoded by the MRE11A gene.

Function

This gene encodes a nuclear protein involved in homologous recombination, telomere length maintenance, and DNA double-strand break repair. By itself, the protein has 3' to 5' exonuclease activity and endonuclease activity. The protein forms a complex with the RAD50 homolog; this complex is required for nonhomologous joining of DNA ends and possesses increased single-stranded DNA endonuclease and 3' to 5' exonuclease activities. In conjunction with a DNA ligase, this protein promotes the joining of noncomplementary ends in vitro using short homologies near the ends of the DNA fragments. This gene has a pseudogene on chromosome 3. Alternative splicing of this gene results in two transcript variants encoding different isoforms.

Orthologs of MRE11A

Mre11, an ortholog of human MRE11A, occurs in the prokaryote archaeon Sulfolobus acidocaldarius. In this organism the Mre11 protein interacts with the Rad50 protein and appears to have an active role in the repair of DNA damages experimentally introduced by gamma radiation. Similarly, during meiosis in the eukaryotic protist Tetrahymena Mre11 is required for repair of DNA damages, in this case double-strand breaks, by a process that likely involves homologous recombination. These observations suggest that human MRE11A is descended from prokaryotic and protist ancestral Mre11 proteins that served a role in early processes for repairing DNA damage.

Meal, Ready-to-Eat

The Meal, Ready-to-Eat – commonly known as the MRE – is a self-contained, individual field ration in lightweight packaging bought by the United States military for its service members for use in combat or other field conditions where organized food facilities are not available. The MRE replaced the canned MCI, or Meal, Combat, Individual rations, in 1981, and is the intended successor to the lighter LRP ration developed by the United States Army for Special Forces and Ranger patrol units in Vietnam.

History

The first soldier ration established by a Congressional Resolution, during the Revolutionary War, consisted of enough food to feed a man for one day, mostly beef, peas, and rice. During the Civil War, the military moved toward canned goods. Later, self-contained kits were issued as a whole ration and contained canned meat, pork, bread, coffee, sugar and salt. During the First World War, canned meats were replaced with lightweight preserved meats (salted or dried) to save weight and allow more rations to be carried by soldiers carrying their supplies on foot. At the beginning of World War II, a number of new field rations were introduced, including the Mountain ration and the Jungle ration. However, cost-cutting measures by Quartermaster Command officials during the latter part of World War II and the Korean War again saw the predominance of heavy canned C rations issued to troops, regardless of operating environment or mission. The use of canned wet rations continued through the Vietnam War, with the improved MCI field ration.

MRE (disambiguation)

MRE is a "Meal, Ready-to-Eat".

MRE may also refer to: