A catalytic triad is a set of three coordinated amino acids that can be found in the active site of some enzymes. Catalytic triads are most commonly found in hydrolase and transferase enzymes. An acid-base-nucleophile triad is a common motif for generating a nucleophilic residue for covalent catalysis. The residues form a charge-relay network to polarise and activate the nucleophile, which attacks the substrate, forming a covalent intermediate which is then hydrolysed to release the product and regenerate free enzyme. The nucleophile is most commonly a serine or cysteine amino acid, but occasionally threonine or even selenocysteine. The 3D structure of the enzyme brings together the triad residues in a precise orientation, even though they may be far apart in the sequence.
Sphingomyelin phosphodiesterase is a hydrolase enzyme that is involved in sphingolipid metabolism reactions. SMase is a member of the DNase I superfamily of enzymes and is responsible for breaking sphingomyelin (SM) down into phosphocholine and ceramide. The activation of SMase has been suggested as a major route for the production of ceramide in response to cellular stresses.
Monoacylglycerol lipase, also known as MAG lipase, acylglycerol lipase, MAGL, MGL or MGLL is an enzyme that, in humans, is encoded by the MGLL gene. MAGL is a 33-kDa, membrane-associated member of the serine hydrolase superfamily and contains the classical GXSXG consensus sequence common to most serine hydrolases. The catalytic triad has been identified as Ser122, His269, and Asp239.
Serine hydrolases are one of the largest known enzyme classes comprising approximately ~200 enzymes or 1% of the genes in the human proteome. A defining characteristic of these enzymes is the presence of a nucleophilic serine in their active site, which is used for the hydrolysis of substrates. Catalysis proceeds by the formation of an acyl-enzyme intermediate through this serine, followed by water/hydroxide-induced saponification of the intermediate and regeneration of the enzyme. Unlike other non-catalytic serines, the nucleophilic serine of these hydrolases is typically activated by a proton relay involving a catalytic triad consisting of the serine, an acidic residue and a basic residue, although variations on this mechanism exist.
Renilla-luciferin 2-monooxygenase, Renilla luciferase, or RLuc, is a bioluminescent enzyme found in Renilla reniformis, belonging to a group of coelenterazine luciferases. Of this group of enzymes, the luciferase from Renilla reniformis has been the most extensively studied, and due to its bioluminescence requiring only molecular oxygen, has a wide range of applications, with uses as a reporter gene probe in cell culture, in vivo imaging, and various other areas of biological research. Recently, chimeras of RLuc have been developed and demonstrated to be the brightest luminescent proteins to date, and have proved effective in both noninvasive single-cell and whole body imaging.
In enzymology, a microsomal epoxide hydrolase (mEH) is an enzyme that catalyzes the hydrolysis reaction between an epoxide and water to form a diol.
In enzymology, a carboxylesterase or carboxylic-ester hydrolase (EC 3.1.1.1) is an enzyme that catalyzes a chemical reaction of the form
In enzymology, an IMP cyclohydrolase (EC 3.5.4.10) is an enzyme that catalyzes the chemical reaction
Carboxylesterase, type B is a family of evolutionarily related proteins.
Liver carboxylesterase 1 also known as carboxylesterase 1 is an enzyme that in humans is encoded by the CES1 gene. The protein is also historically known as serine esterase 1 (SES1), monocyte esterase and cholesterol ester hydrolase (CEH). Three transcript variants encoding three different isoforms have been found for this gene. The various protein products from isoform a, b and c range in size from 568, 567 and 566 amino acids long, respectively.
1-acylglycerol-3-phosphate O-acyltransferase ABHD5 is an enzyme that in humans is encoded by the ABHD5 gene.
Abhydrolase domain-containing protein 2 is a serine hydrolase enzyme that is strongly expressed in human spermatozoa. It is a key controller of sperm hyperactivation, which is a necessary step in allowing sperm to fertilize an egg. It is encoded by the ABHD2 gene.
Nudix hydrolases are a superfamily of hydrolytic enzymes capable of cleaving nucleoside diphosphates linked to x, hence their name. The reaction yields nucleoside monophosphate (NMP) plus X-P. Substrates hydrolysed by nudix enzymes comprise a wide range of organic pyrophosphates, including nucleoside di- and triphosphates, dinucleoside and diphosphoinositol polyphosphates, nucleotide sugars and RNA caps, with varying degrees of substrate specificity. Enzymes of the Nudix superfamily are found in all types of organisms, including eukaryotes, bacteria and archaea.
In molecular biology, glycoside hydrolase family 97 is a family of glycoside hydrolases.
In molecular biology, glycoside hydrolase family 36 is a family of glycoside hydrolases.
In molecular biology, the YjeF N terminal is a protein domain found in the N-terminal of the protein, EDC3. The YjeF N-terminal domains occur either as single proteins or fusions with other domains and are commonly associated with enzymes. They help assemble the processing body (P-body) in preparation for mRNAdecay. Structural homology indicated it may have some similarity to the enzyme family, hydrolase.
(S)-hydroxynitrile lyase is an enzyme with systematic name (S)-cyanohydrin lyase . This enzyme catalyses the interconversion between cyanohydrins and the carbonyl compounds derived from the cyanohydrin with free cyanide, as in the following two chemical reactions:
A protein superfamily is the largest grouping (clade) of proteins for which common ancestry can be inferred. Usually this common ancestry is inferred from structural alignment and mechanistic similarity, even if no sequence similarity is evident. Sequence homology can then be deduced even if not apparent. Superfamilies typically contain several protein families which show sequence similarity within each family. The term protein clan is commonly used for protease and glycosyl hydrolases superfamilies based on the MEROPS and CAZy classification systems.
alpha/beta-Hydrolase domain containing 6 (ABHD6), also known as monoacylglycerol lipase ABHD6 or 2-arachidonoylglycerol hydrolase is an enzyme that in humans is encoded by the ABHD6 gene.
The Enzyme MHETase is a hydrolase, which was discovered in 2016. It cleaves Mono-(2-hydroxyethyl)terephthalic acid, the PET degradation product by PETase, to ethylene glycol and terephthalic acid. This pair of enzymes, PETase and MHETase, enable the bacterium Ideonella sakaiensis to live on the plastic PET as sole carbon source.
