In molecular biology, Glutamate formimidoyltransferase is a methyltransferase

Methyltransferase

A methyltransferase is a type of transferase enzyme that transfers a methyl group from a donor to an acceptor.Methylation often occurs on nucleic bases in DNA or amino acids in protein structures...

 enzyme which uses tetrahydrofolate as part of histidine

Histidine

Histidine Histidine, an essential amino acid, has a positively charged imidazole functional group. It is one of the 22 proteinogenic amino acids. Its codons are CAU and CAC. Histidine was first isolated by German physician Albrecht Kossel in 1896. Histidine is an essential amino acid in humans...

 catabolism

Catabolism

Catabolism is the set of metabolic pathways that break down molecules into smaller units and release energy. In catabolism, large molecules such as polysaccharides, lipids, nucleic acids and proteins are broken down into smaller units such as monosaccharides, fatty acids, nucleotides, and amino...

. It catalyses two reactions:

• 5-formimidoyltetrahydrofolate + L-glutamate <=> tetrahydrofolate + N-formimidoyl-L-glutamate

• 5-formyltetrahydrofolate + L-glutamate <=> tetrahydrofolate + N-formyl-L-glutamate

It is classified under and in mammals is found as part of a bifunctional enzyme that also has formimidoyltetrahydrofolate cyclodeaminase

Formimidoyltetrahydrofolate cyclodeaminase

In enzymology, a formimidoyltetrahydrofolate cyclodeaminase is an enzyme that catalyzes the chemical reactionHence, this enzyme has one substrate, 5-formimidoyltetrahydrofolate, and two products, 5,10-methenyltetrahydrofolate and NH3....

 activity.

Structure

The formiminotransferase (FT) domain

Protein domain

A protein domain is a part of protein sequence and structure that can evolve, function, and exist independently of the rest of the protein chain. Each domain forms a compact three-dimensional structure and often can be independently stable and folded. Many proteins consist of several structural...

 of formiminotransferase-cyclodeaminase (FTCD) forms a homodimer, with each protomer comprising two subdomains. The formiminotransferase domain has an N-terminal subdomain that is made up of a six-stranded mixed beta-pleated sheet and five alpha helices, which are arranged on the external surface of the beta sheet

Beta sheet

The β sheet is the second form of regular secondary structure in proteins, only somewhat less common than the alpha helix. Beta sheets consist of beta strands connected laterally by at least two or three backbone hydrogen bonds, forming a generally twisted, pleated sheet...

. This, in turn, faces the beta-sheet of the C-terminal subdomain to form a double beta-sheet layer. The two subdomains are separated by a short linker sequence, which is not thought to be any more flexible than the remainder of the molecule

Molecule

A molecule is an electrically neutral group of at least two atoms held together by covalent chemical bonds. Molecules are distinguished from ions by their electrical charge...

. The substrate is predicted to form a number of contacts with residue

Residue

Residue may refer to:* Residue , material remaining after a distillation or an evaporation, or portion of a larger molecule** In particular, in biology, often refers specifically to an amino acid...

s found in both the N-terminal and C-terminal subdomains. In humans, deficiency of this enzyme

Enzyme

Enzymes are proteins that catalyze chemical reactions. In enzymatic reactions, the molecules at the beginning of the process, called substrates, are converted into different molecules, called products. Almost all chemical reactions in a biological cell need enzymes in order to occur at rates...

 results in a disease

Disease

A disease is an abnormal condition affecting the body of an organism. It is often construed to be a medical condition associated with specific symptoms and signs. It may be caused by external factors, such as infectious disease, or it may be caused by internal dysfunctions, such as autoimmune...

 phenotype

Phenotype

A phenotype is an organism's observable characteristics or traits: such as its morphology, development, biochemical or physiological properties, behavior, and products of behavior...

.

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