In biology and biochemistry, protease inhibitors, or antiproteases, are molecules that inhibit the function of proteases. Many naturally occurring protease inhibitors are proteins.
Carbamoyl phosphate synthetase catalyzes the ATP-dependent synthesis of carbamoyl phosphate from glutamine or ammonia and bicarbonate. This enzyme catalyzes the reaction of ATP and bicarbonate to produce carboxy phosphate and ADP. Carboxy phosphate reacts with ammonia to give carbamic acid. In turn, carbamic acid reacts with a second ATP to give carbamoyl phosphate plus ADP.
Formimidoyltransferase cyclodeaminase or formiminotransferase cyclodeaminase is a bifunctional enzyme that catalyzes the following reactions:
In enzymology, a homoserine dehydrogenase (EC 1.1.1.3) is an enzyme that catalyzes the chemical reaction
In enzymology, a protein-glutamate O-methyltransferase is an enzyme that catalyzes the chemical reaction
In enzymology, a L-fucose isomerase is an enzyme that catalyzes the chemical reaction
In enzymology, a formimidoyltetrahydrofolate cyclodeaminase (EC 4.3.1.4) is an enzyme that catalyzes the chemical reaction
In enzymology, a formate—tetrahydrofolate ligase is an enzyme that catalyzes the chemical reaction
In enzymology, an ATP phosphoribosyltransferase is an enzyme that catalyzes the chemical reaction
In enzymology, a riboflavin kinase is an enzyme that catalyzes the chemical reaction
Methylenetetrahydrofolate dehydrogenase, cyclohydrolase and formyltetrahydrofolate synthetase 1 (MTHFD1) is a gene located in humans on chromosome 14 that encodes a protein, C-1-tetrahydrofolate synthase, cytoplasmic also known as C1-THF synthase, with three distinct enzymatic activities.
In molecular biology, the AMMECR1 protein is a protein encoded by the AMMECR1 gene on human chromosome Xq22.3.
Biopterin-dependent aromatic amino acid hydroxylases (AAAH) are a family of aromatic amino acid hydroxylase enzymes which includes phenylalanine 4-hydroxylase, tyrosine 3-hydroxylase, and tryptophan 5-hydroxylase. These enzymes primarily hydroxylate the amino acids L-phenylalanine, L-tyrosine, and L-tryptophan, respectively.
In molecular biology, a carbohydrate-binding module (CBM) is a protein domain found in carbohydrate-active enzymes. The majority of these domains have carbohydrate-binding activity. Some of these domains are found on cellulosomal scaffoldin proteins. CBMs were previously known as cellulose-binding domains. CBMs are classified into numerous families, based on amino acid sequence similarity. There are currently 64 families of CBM in the CAZy database.
In molecular biology, the CDC48 N-terminal domain is a protein domain found in AAA ATPases including cell division protein 48 (CDC48), VCP-like ATPase and N-ethylmaleimide sensitive fusion protein. It is a substrate recognition domain which binds polypeptides, prevents protein aggregation, and catalyses refolding of permissive substrates. It is composed of two equally sized subdomains. The amino-terminal subdomain (CDC48_N) forms a double-psi beta-barrel whose pseudo-twofold symmetry is mirrored by an internal sequence repeat of 42 residues. The carboxy-terminal subdomain (CDC48_2) forms a novel six-stranded beta-clam fold. Together these subdomains form a kidney-shaped structure, in close agreement with results from electron microscopy. CDC48_N is related to numerous proteins including prokaryotic transcription factors, metabolic enzymes, the protease cofactors UFD1 and PrlF, and aspartic proteinases.
In molecular biology, multicopper oxidases are enzymes which oxidise their substrate by accepting electrons at a mononuclear copper centre and transferring them to a trinuclear copper centre; dioxygen binds to the trinuclear centre and, following the transfer of four electrons, is reduced to two molecules of water. There are three spectroscopically different copper centres found in multicopper oxidases: type 1, type 2 and type 3. Multicopper oxidases consist of 2, 3 or 6 of these homologous domains, which also share homology with the cupredoxins azurin and plastocyanin. Structurally, these domains consist of a cupredoxin-like fold, a beta-sandwich consisting of 7 strands in 2 beta-sheets, arranged in a Greek-key beta-barrel.
In molecular biology, D-stereospecific aminopeptidase (D-aminopeptidase) EC 3.4.11.19 is an enzyme which catalyses the release of an N-terminal D-amino acid from a peptide, Xaa-|-Yaa-, in which Xaa is preferably D-Ala, D-Ser or D-Thr. D-amino acid amides and methyl esters also are hydrolyzed, as is glycine amide.
The prokaryotic riboflavin biosynthesis protein is a bifunctional enzyme found in bacteria that catalyzes the phosphorylation of riboflavin into flavin mononucleotide (FMN) and the adenylylation of FMN into flavin adenine dinucleotide (FAD). It consists of a C-terminal riboflavin kinase and an N-terminal FMN-adenylyltransferase. This bacterial protein is functionally similar to the monofunctional riboflavin kinases and FMN-adenylyltransferases of eukaryotic organisms, but only the riboflavin kinases are structurally homologous.
In molecular biology, enzymes containing the cyclodeaminase domain function in channeling one-carbon units to the folate pool. In most cases, this domain acts as a formimidoyltetrahydrofolate cyclodeaminase, which catalyses the cyclisation of formimidoyltetrahydrofolate to methenyltetrahydrofolate as shown in reaction (1). In the methylotrophic bacterium Methylobacterium extorquens, however, it acts as a methenyltetrahydrofolate cyclohydrolase, which catalyses the interconversion of formyltetrahydrofolate and methylenetetrahydrofolate, as shown in reaction (2).
In molecular biology, glycoside hydrolase family 65 is a family of glycoside hydrolases.
