Amino acid synthesis is the set of biochemical processes by which the amino acids are produced. The substrates for these processes are various compounds in the organism's diet or growth media. Not all organisms are able to synthesize all amino acids. For example, humans can synthesize 11 of the 20 standard amino acids. These 11 are called the non-essential amino acids).
(E)-4-Hydroxy-3-methyl-but-2-enyl pyrophosphate (HMBPP or HMB-PP) is an intermediate of the MEP pathway (non-mevalonate pathway) of isoprenoid biosynthesis. The enzyme HMB-PP synthase (GcpE, IspG) catalyzes the conversion of 2-C-methyl-D-erythritol 2,4-cyclodiphosphate (MEcPP) into HMB-PP. HMB-PP is then converted further to isopentenyl pyrophosphate (IPP) and dimethylallyl pyrophosphate (DMAPP) by HMB-PP reductase (LytB, IspH).
The non-mevalonate pathway—also appearing as the mevalonate-independent pathway and the 2-C-methyl-D-erythritol 4-phosphate/1-deoxy-D-xylulose 5-phosphate (MEP/DOXP) pathway—is an alternative metabolic pathway for the biosynthesis of the isoprenoid precursors isopentenyl pyrophosphate (IPP) and dimethylallyl pyrophosphate (DMAPP). The currently preferred name for this pathway is the MEP pathway, since MEP is the first committed metabolite on the route to IPP.
The transsulfuration pathway is a metabolic pathway involving the interconversion of cysteine and homocysteine through the intermediate cystathionine. Two transsulfurylation pathways are known: the forward and the reverse.
DXP reductoisomerase is an enzyme that interconverts 1-deoxy-D-xylulose 5-phosphate (DXP) and 2-C-methyl-D-erythritol 4-phosphate (MEP).
In enzymology, a 4-hydroxy-3-methylbut-2-en-1-yl diphosphate synthase (HMB-PP synthase, IspG, EC 1.17.7.1) is an enzyme that catalyzes the chemical reaction
The enzyme aminocyclopropane-1-carboxylic acid synthase catalyzes the synthesis of 1-Aminocyclopropane-1-carboxylic acid (ACC), a precursor for ethylene, from S-Adenosyl methionine, an intermediate in the Yang cycle and activated methyl cycle and a useful molecule for methyl transfer:
Cystathionine beta-lyase, also commonly referred to as CBL or β-cystathionase, is an enzyme that primarily catalyzes the following α,β-elimination reaction
The enzyme 3-dehydroquinate synthase catalyzes the chemical reaction
The enzyme chorismate synthase catalyzes the chemical reaction
In enzymology, a 2-C-methyl-D-erythritol 4-phosphate cytidylyltransferase is an enzyme that catalyzes the chemical reaction:
In enzymology, a 4-(cytidine 5'-diphospho)-2-C-methyl-D-erythritol kinase is an enzyme that catalyzes the chemical reaction
2-C-Methyl-d-erythritol-2,4-cyclopyrophosphate (MEcPP) is an intermediate in the MEP pathway (non-mevalonate) of isoprenoid precursor biosynthesis. MEcPP is produced by MEcPP synthase (IspF) and is a substrate for HMB-PP synthase (IspG).
4-Diphosphocytidyl-2-C-methylerythritol is an intermediate in the MEP pathway of isoprenoid precursor biosynthesis. It is produced by the enzyme 2-C-methyl-D-erythritol 4-phosphate cytidylyltransferase (IspD) and is a substrate for CDP-ME kinase (IspE).
4-Diphosphocytidyl-2-C-methyl-D-erythritol 2-phosphate is an intermediate in the MEP pathway of isoprenoid precursor biosynthesis.
4-Hydroxy-3-methylbut-2-enyl diphosphate reductase (EC 1.17.1.2, isopentenyl-diphosphate:NADP+ oxidoreductase, LytB, (E)-4-hydroxy-3-methylbut-2-en-1-yl diphosphate reductase, HMBPP reductase, IspH, LytB/IspH) is an enzyme in the non-mevalonate pathway. It acts upon (E)-4-Hydroxy-3-methyl-but-2-enyl pyrophosphate (or "HMB-PP").
Cobalamin biosynthesis is the process by which bacteria and archea make cobalamin, vitamin B12. Many steps are involved in converting aminolevulinic acid via uroporphyrinogen III and adenosylcobyric acid to the final forms in which it is used by enzymes in both the producing organisms and other species, including humans who acquire it through their diet.
3-Deoxy-D-arabinoheptulosonate 7-phosphate (DAHP) synthase is the first enzyme in a series of metabolic reactions known as the shikimate pathway, which is responsible for the biosynthesis of the amino acids phenylalanine, tyrosine, and tryptophan. Since it is the first enzyme in the shikimate pathway, it controls the amount of carbon entering the pathway. Enzyme inhibition is the primary method of regulating the amount of carbon entering the pathway. Forms of this enzyme differ between organisms, but can be considered DAHP synthase based upon the reaction that is catalyzed by this enzyme.
In molecular biology, YgbB is a protein domain. This entry makes reference to a number of proteins from eukaryotes and prokaryotes which share this common N-terminal signature and appear to be involved in terpenoid biosynthesis. The YgbB protein is a putative enzyme thought to aid terpenoid and isoprenoid biosynthesis, a vital chemical in all living organisms. This protein domain is part of an enzyme which catalyses a reaction in a complex pathway.
Radical SAM is a designation for a superfamily of enzymes that use a [4Fe-4S]+ cluster to reductively cleave S-adenosyl-L-methionine (SAM) to generate a radical, usually a 5′-deoxyadenosyl radical (5'-dAdo), as a critical intermediate. These enzymes utilize this radical intermediate to perform diverse transformations, often to functionalize unactivated C-H bonds. Radical SAM enzymes are involved in cofactor biosynthesis, enzyme activation, peptide modification, post-transcriptional and post-translational modifications, metalloprotein cluster formation, tRNA modification, lipid metabolism, biosynthesis of antibiotics and natural products etc. The vast majority of known radical SAM enzymes belong to the radical SAM superfamily, and have a cysteine-rich motif that matches or resembles CxxxCxxC. rSAMs comprise the largest superfamily of metal-containing enzymes.
