The researchers, from the University of Minnesota and Dartmouth College, also report that the gene, bears a striking similarity to genes of unknown function in rice, yeast, worms and humans. This suggests that the gene, which was cloned from a small plant related to the mustard family, may be part of a new class of genes involved in controlling the uptake of metals by cells. When the researchers compared the gene's code to those stored in a data bank containing sequences from hundreds of other organisms, they discovered several closely related sequences, suggesting that they may have discovered a new family of metal transport genes. David Eide, a microbiologist at the University of Minnesota School of Medicine, and Mary Lou Guerinot, a biologist at Dartmouth College, reported the discovery in the current issue of Proceedings of the National Academy of Sciences. More than a third of the world's soils are iron- deficient, compromising soil fertility.
Iron deficiency is also the leading nutritional disorder in people worldwide.
Most of the world's humans get their daily iron supply in the form of plant foods. Though iron deficiency is a global nutrition problem, iron overload is lethal to people with an inherited disorder called hemochromatosis, which causes their bodies to store excess iron. Iron has also been implicated as a risk factor in heart disease. This protein converts an unusable form of iron in soil into a form that can be taken up by cells. Yeast use a similar mechanism to obtain iron.