MTR is an enzyme that is necessary for the conversion of homocysteine to methionine. Methionine production is important as it is crucial for ‘DNA methylation’ - the process by which our genes are turned ‘on’ and ‘off’.
Source: 1000 Genome Project. Global averages for both sexes
Folate and impacts on Homocysteine.
It is estimated that 5-10% of the population has homocysteine levels that are considered high. High levels of homocysteine in our bodies are not good for optimal health, and it is known to be a biomarker for certain conditions such as cardiovascular health. As a result, it is important that we maintain healthy levels of this naturally occurring amino acid by maintaining the right balance in the folate and methionine cycles. High homocysteine levels may be caused by:
1) Not enough active folate to drive conversion of homocysteine to methionine, either as a result of: • lack of folate in the diet, or • reduced efficiency of the MTHFR enzyme that converts dietary folate/folic acid to active folate
2) Reduced efficiency of the MTR/ MTRR enzymes that convert homocysteine to methionine.
Vitamins B2, B6 and B12 are also important co-factors in these reactions.
The functional integrity of any one of the enzymes and other factors regulating these pathways is important in maintaining the healthy running of these cycles. Occasionally genetic variants in the genes encoding these enzymes can impact on how able each enzyme is at doing its job, reducing our body’s efficiency in DNA synthesis and methylation as a result.