What does methionine synthase reductase do?
[Methionine synthase] reductase, or Methionine synthase reductase, encoded by the gene MTRR, is an enzyme that is responsible for the reduction of methionine synthase inside human body. This enzyme is crucial for maintaining the one carbon metabolism, specifically the folate cycle.
What is the cofactor for methionine synthase?
cobalamin
Methionine synthase is known to promote methyl group transfer from methylated folate to homocysteine to yield methionine. This reaction is supported by cobalamin as a cofactor in methionine synthase.
What does MTRR stand for?
5-methyltetrahydrofolate-homocysteine methyltransferase reductase.
Where is methionine synthase found?
Chromosome 1
Methionine synthase
| Gene location (Human) | ||
|---|---|---|
| Chr. | Chromosome 1 (human) | |
| Band | 1q43 | Start |
| End |
What is the folate cycle?
The folate cycle provides one-carbon units for an extensive metabolic network that fuels the methionine cycle, transsulfuration pathway, de novo purine synthesis, thymidine production, serine, glycine, glutathione, and NADPH pools, and thereby regulates cellular redox state, growth, and proliferation16,36.
What role is played by vitamin b12 cobalamin to methionine synthase?
Vitamin B-12 is a cofactor for 2 enzymes. In the cytoplasm, methionine synthase requires vitamin B-12 in the form of methylcobalamin and catalyzes the conversion of homocysteine to methionine by transfer of a methyl group from methyltetrahydrofolate.
What is the CBS gene?
The CBS gene provides instructions for making an enzyme called cystathionine beta-synthase. This enzyme acts in a chemical pathway and is responsible for using vitamin B6 to convert building block of proteins (amino acid) called homocysteine and serine to a molecule called cytathionine.
What is Mtrr gene mutation?
More than 20 mutations in the MTR gene have been identified in people with homocystinuria. Many of these mutations lead to the production of an abnormally small, nonfunctional version of methionine synthase. Other mutations change single amino acids in the enzyme.
Is methionine synthase the same as homocysteine methyltransferase?
This gene encodes the 5-methyltetrahydrofolate-homocysteine methyltransferase. This enzyme, also known as cobalamin-dependent methionine synthase, catalyzes the final step in methionine biosynthesis. Mutations in MTR have been identified as the underlying cause of methylcobalamin deficiency complementation group G.
What is methylenetetrahydrofolate reductase polymorphism?
A common genetic polymorphism results from a C→T substitution in the gene encoding methylenetetrahydrofolate reductase (MTHFR), the enzyme that produces 5-methyltetrahydrofolate (5-methyl-THF) required for the conversion of homocysteine to methionine.
What does the methionine cycle do?
The methionine cycle, via the de novo arm, produces the primary methyl donor AdoMet for the transmethylation of proteins, nucleic acids and other molecules, with far-reaching regulatory roles. Along the route it also yields homocysteine whose own metabolism is at the crossroads of several pathways.
What is the role of cyanocobalamin in methionine metabolism?
Vitamin B12 (cobalamin) plays a vital role in the conversion of homocysteine to methionine in methionine cycle, since it takes the methyl group from 5-methyl tetrahydrofolate (folic acid) and forms methyl cobalamin which then releases this methyl group in order to convert homocysteine into methionine.
What is the role of homocysteine?
Homocysteine is an amino acid. Vitamins B12, B6 and folate break down homocysteine to create other chemicals your body needs. High homocysteine levels may mean you have a vitamin deficiency. Without treatment, elevated homocysteine increases your risks for dementia, heart disease and stroke.
What is MMA and homocysteine?
Serum homocysteine and methylmalonic acid (MMA) levels are helpful confirmatory tests for cobalamin and folate deficiencies. Both are increased in cobalamine deficiency. Homocysteine but not MMA is increased in folate deficiency.
What is a function of CBS?
Normal Function The CBS gene provides instructions for making an enzyme called cystathionine beta-synthase. This enzyme acts in a chemical pathway and is responsible for using vitamin B6 to convert building block of proteins (amino acid) called homocysteine and serine to a molecule called cytathionine.
What is CBS mutation?
Mutations of the CBS gene may result in reduced activity of the cystathionine beta-synthase enzyme, which is involved in the conversion of the essential amino acid methionine to another amino acid (cysteine).