methionine adenosyltransferase 1A

Normal function

The MAT1A gene provides instructions for producing the enzyme methionine adenosyltransferase. The enzyme is produced from the MAT1A gene in two forms, designated MATI and MATII. MATI is made up of four identical protein subunits, which is known as a homotetramer. MATII is made up of two of the same protein subunits, which is known as a homodimer. Both forms of the enzyme are found in the liver.

Both the MATI and MATII forms of methionine adenosyltransferase help break down a protein building block (amino acid) called methionine. The enzyme starts the reaction that converts methionine to S-adenosylmethionine, also called AdoMet or SAMe. AdoMet is involved in transferring methyl groups, consisting of a carbon atom and three hydrogen atoms, to other compounds, a process called transmethylation. Transmethylation is important in many cellular processes. These processes include determining whether the instructions in a particular segment of DNA are carried out, regulating reactions involving proteins and lipids, and controlling the processing of chemicals that relay signals in the nervous system (neurotransmitters).

Conditions referring to this gene or chromosome

• Hypermethioninemia

Other names

MAT

MATA1

methionine adenosyltransferase I, alpha

METK1_HUMAN

S-adenosylmethionine synthetase 1

SAMS

SAMS, liver-specific

SAMS1