Enzymes are listed here by their classification in the International Union of Biochemistry and Molecular Biology's Enzyme Commission (EC) numbering system:
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Transcription
So today, we're going to talk about enzymes and all the different kinds of reactions that enzymes can catalyze. But before we do that, let's review the idea that enzymes make biochemical reactions go faster. And if you look at a reaction coordinate diagram, you'd notice that enzymes speed up reactions by lowering their activation energy. Now, enzymes are generally named for their reactions, which is convenient because it makes it a lot easier to remember what an enzyme does if someone gives you its name. And a great example of this is that one of the enzymes involved in DNA replication is called DNA polymerase, which is named as such because it acts on DNA and specifically makes polymers of DNA. Now, the suffix "ase" is usually just one that you find at the end of most enzyme names. Now, another great example is that the enzyme that catalyzes the first step of glycolysis, which you may remember is the reaction between glucose and ATP to form glucose-6-phosphate and ADP, is called hexokinase. And "hexo" refers to the number 6, which is a reference to glucose being a six-carbon sugar. And "kinase" is a term referring to enzymes that add phosphate functional groups to different substrates. So overall, hexokinase adds phosphates to six-carbon sugars like glucose. Now generally, every enzyme has a very specific name that gives insight into the specific reaction that that enzyme can catalyze. So we can actually divide most enzymes into six different categories based off the kinds of reactions that they catalyze. Now, our first group is the transferase group. And the basic reaction that transferases catalyze are ones where you move some functional group, X, from molecule B to molecule A. And a great example of one of these reactions occurs during protein translation, where amino acids bound to tRNA molecules are transferred over to the growing polypeptide chain. So in this case, A refers to our amino acid chain, B refers to our tRNA, and X refers to this lysine residue, which is being transferred from B to A. And this reaction in particular is catalyzed by an enzyme called peptidyl transferase, which is an appropriate name since it is a transferase involved in making peptides. Next we have the ligase group, which catalyzes reactions between two molecules, A and B, that are combining to form a complex between the two, or AB. And an example of a reaction using a ligase that you might be familiar with occurs during DNA replication, where two strands of DNA are being joined together. So in this reaction, A and B represent the two separated DNA polymers, which are being joined to form a single strand. And this reaction in particular is catalyzed by an enzyme called DNA ligase, which is named since it's a ligase that works on DNA strands. Now our third group as the oxidoreductase group, which is a little different from the others since it actually includes two different types of reactions. And these reactions involve transferring electrons from either molecule B to molecule A or from molecule A to molecule B. Now, we say that an oxidase is directly involved in oxidizing or taking electrons away from a molecule, while a reductase is involved in reducing or giving electrons to a molecule. And we call these enzymes oxidoreductases together because they can usually catalyze both the forward and reverse reactions, which is why I used equilibrium arrows here instead of just a normal single-headed arrow. Now a great example of an oxidation reduction reaction occurs during lactic acid fermentation, where electrons are either passed from NADH to pyruvate or from lactic acid to NAD. Now, this reaction is catalyzed by an enzyme called lactate dehydrogenase. Remember that the word "dehydrogenase" refers to the removal of a hydride functional group. And that's the same as saying the removal of electrons, since hydrides are basically just hydrogen atoms with two electrons on them instead of just one. Now, this enzyme is given its name since it's able to remove a hydride, or remove electrons, from a molecule of lactic acid. Next, we have the isomerase group. And enzymes in this group are typically involved in reactions where a molecule, like molecule A, is being converted to one of its isomers. And an example of this type of a reaction is the conversion of glucose-6-phostate to fructose-6-phosphate, which is one of the steps of glycolysis that you may remember. Now, this reaction is catalyzed by an enzyme called phosphoglucose isomerase, which is appropriately named since it creates isomers of glucose molecules that are phosphorylated. Now, our next category is the hydrolase category. And hydrolases use water to cleave a molecule, like molecule A, into two other molecules, B and C. And a great example of one of these reactions is the hydrolysis reaction that can occur to peptide bonds. And if we have this lysine-alanine dipeptide here, it could be reacted with water to form two individual amino acids that are no longer bound. And this particular hydrolysis reaction can be catalyzed by a class of enzymes that we call serine hydrolases, which some people call serine proteases. And they are named this way because they are hydrolases that use a serine residue as the key catalytic amino acid that is responsible for breaking the peptide bond. Now, our last category is a little more complicated than the others. And it's the lyase group. Now, lyases catalyze the dissociation of a molecule, like molecule A, into molecule B and C, without using water like hydrolases would, and without using oxidation or reduction like an oxidoreductase would. And one example of a reaction catalyzed by a lyase is the cleavage of argininosuccinate into arginine and succinate. And this reaction takes place during the urea cycle, which you also might be familiar with. Now this specific reaction is catalyzed by an enzyme called argininosuccinate lyase, which is appropriately named because it is a lyase that catalyzes the breakdown of an argininosuccinate molecule. Now, it's important to recognize that since lyases don't use water or oxidation to break a bond, they need to generate either a double bond between two atoms or a ring structure in a molecule in order to work. So what did we learn? Well, first we learned that enzymes are sometimes named for their reactions. And next we learned about the six different types of enzymes. We have transferases, which transfer functional groups from one molecule to another; ligases, which ligate or join two molecules together; oxidoreductases, which move electrons between molecules; isomerases, which convert a molecule from one isomer to another; hydrolases, which break bonds using water; and lyases, which break bonds without using water and without using oxidation.
Category:Oxidoreductases (EC 1) (Oxidoreductase)
Category:EC 1.1 (act on the CH-OH group of donors)
- Category:EC 1.1.1 (with NAD+ or NADP+ as acceptor)
- Alcohol dehydrogenase (NAD) EC 1.1.1.1
- Alcohol dehydrogenase (NADP) EC 1.1.1.2
- Homoserine dehydrogenase EC 1.1.1.3
- Aminopropanol oxidoreductase EC 1.1.1.4
- Diacetyl reductase EC 1.1.1.5
- Glycerol dehydrogenase EC 1.1.1.6
- Propanediol-phosphate dehydrogenase EC 1.1.1.7
- glycerol-3-phoshitiendopene dehydrogenase (NAD+) EC 1.1.1.8
- D-xylulose reductase EC 1.1.1.9
- L-xylulose reductase EC 1.1.1.10
- Lactate dehydrogenase EC 1.1.1.27
- Malate dehydrogenase EC 1.1.1.37
- Isocitrate dehydrogenase EC 1.1.1.42
- HMG-CoA reductase EC 1.1.1.88
- Category:EC 1.1.2 (with a cytochrome as acceptor)
- Category:EC 1.1.3 (with oxygen as acceptor)
- Category:EC 1.1.4 (with a disulfide as acceptor)
- Category:EC 1.1.5 (with a quinone or similar compound as acceptor)
- Category:EC 1.1.99 (with other acceptors)
Category:EC 1.2 (act on the aldehyde or oxo group of donors)
- Category:EC 1.2.1 (with NAD+ or NADP+ as acceptor)
- Category:EC 1.2.4
Category:EC 1.3 (act on the CH-CH group of donors)
- Category:EC 1.3.1 (with NAD+ or NADP+ as acceptor)
- Category:EC 1.3.2 (with a cytochrome as acceptor)
- Category:EC 1.3.3 (with oxygen as acceptor)
- Category:EC 1.3.5 (with a quinone or similar compound as acceptor)
- Category:EC 1.3.7 (with an iron–sulfur protein as acceptor)
- Category:EC 1.3.99 (with other acceptors)
Category:EC 1.4 (act on the CH-NH2 group of donors)
Category:EC 1.5 (act on CH-NH group of donors)
- Category:EC 1.5.1 (with NAD+ or NADP+ as acceptor)
- Category:EC 1.5.3 (with oxygen as acceptor)
- Category:EC 1.5.4 (with a disulfide as acceptor)
- Category:EC 1.5.5 (with a quinone or similar compound as acceptor)
- Category:EC 1.5.7 (with an iron–sulfur protein as acceptor)
- Category:EC 1.5.8 (with a flavin as acceptor)
- Category:EC 1.5.99 (with other acceptors)
Category:EC 1.6 (act on NADH or NADPH)
- Category:EC 1.6.1 (with NAD+ or NADP+ as acceptor)
- Category:EC 1.6.2 (with a cytochrome as acceptor)
- Category:EC 1.6.3 (with oxygen as acceptor)
- Category:EC 1.6.4 now Category:EC 1.8.1
- Category:EC 1.6.5 (with a quinone or similar compound as acceptor)
- Category:EC 1.6.6 (with a nitrogenous group as acceptor)
- Category:EC 1.6.7 now Category:EC 1.18.1
- Category:EC 1.6.8 now Category:EC 1.5.1
- Category:EC 1.6.99 (with other acceptors)
Category:EC 1.7 (act on other nitrogenous compounds as donors)
- Category:EC 1.7.1 (with NAD+ or NADP+ as acceptor)
- Category:EC 1.7.2 (with a cytochrome as acceptor)
- Category:EC 1.7.3 (with oxygen as acceptor)
- Category:EC 1.7.7 (with an iron–sulfur protein as acceptor)
- Category:EC 1.7.99 (with other acceptors)
Category:EC 1.8 (act on a sulfur group of donors)
- Category:EC 1.8.1 (with NAD+ or NADP+ as acceptor)
- Category:EC 1.8.2 (with a cytochrome as acceptor)
- Category:EC 1.8.3 (with oxygen as acceptor)
- Category:EC 1.8.4 (with a disulfide as acceptor)
- Category:EC 1.8.5 (with a quinone or similar compound as acceptor)
- Category:EC 1.8.6 deleted, included in EC 2.5.1.18
- Category:EC 1.8.7 (with an iron–sulfur protein as acceptor)
- Category:EC 1.8.98 (with other, known, acceptors)
- Category:EC 1.8.99 (with other acceptors)
Category:EC 1.9 (act on a heme group of donors)
- Category:EC 1.9.3 (with oxygen as acceptor)
- Category:EC 1.9.6 (with a nitrogenous as acceptor)
- Category:EC 1.9.99 transferred, now EC 1.9.98.1
- Category:EC 1.10.1(with NAD+ or NADP+ as acceptor)
- Category:EC 1.10.2 (with a cytochrome as acceptor)
- Category:EC 1.10.3 (with oxygen as acceptor)
- Category:EC 1.10.99 (with other acceptors)
Category:EC 1.11 (act on peroxide as an acceptor -- peroxidases)
Category:EC 1.12 (act on hydrogen as a donor)
- Category:EC 1.12.1 (with NAD+ or NADP+ as acceptor)
- Category:EC 1.12.2 (with a cytochrome as acceptor)
- Category:EC 1.12.5 (with a quinone or similar compound as acceptor)
- Category:EC 1.12.7 (with an iron–sulfur protein as acceptor)
- Category:EC 1.12.98 (with other known acceptors)
- Category:EC 1.12.99 (with other acceptors)
Category:EC 1.13 (act on single donors with incorporation of molecular oxygen)
- Category:EC 1.13.11 (With incorporation of two atoms of oxygen)
- Category:EC 1.13.12 (With incorporation of one atom of oxygen (internal monooxygenases or internal mixed function oxidases))
Category:EC 1.14 (act on paired donors with incorporation of molecular oxygen)
- Cytochrome P450 oxidase
- Category:Cytochrome P450
- Category:EC 1.14.12
- Category:EC 1.14.13
- Category:EC 1.14.14
- Category:EC 1.14.16
- Category:EC 1.14.18
Category:EC 1.15 (act on superoxide radicals as acceptors)
Category:EC 1.16 (oxidize metal ions)
Category:EC 1.17 (act on CH or CH2 groups)
- Category:EC 1.17.1
- Category:EC 1.17.2
- Category:EC 1.17.3
- Category:EC 1.17.4
- Category:EC 1.17.5
- Category:EC 1.17.7
- Category:EC 1.17.99
Category:EC 1.18 (act on iron–sulfur proteins as donors)
Category:EC 1.19 (act on reduced flavodoxin as donor)
Category:EC 1.20 (act on phosphorus or arsenic as donors)
Category:EC 1.21 (act on X-H and Y-H to form an X-Y bond)
Category:EC 1.97 (other oxidoreductases)
Category:Transferases (EC 2) (Transferase)
Category:EC 2.1 (transfer one-carbon groups, Methylase)
Category:EC 2.2 (transfer aldehyde or ketone groups)
Category:EC 2.3 (acyltransferases)
Category:EC 2.4 (glycosyltransferases)
Category:EC 2.5 (transfer alkyl or aryl groups, other than methyl groups)
Category:EC 2.6 (transfer nitrogenous groups)
Category:EC 2.7 (transfer phosphorus-containing groups)
Category:EC 2.8 (transfer sulfur-containing groups)
- EC 2.8.1.1: Thiosulfate sulfurtransferase
- EC 2.8.1.2: 3-mercaptopyruvate sulfurtransferase
- EC 2.8.1.3: Thiosulfate—thiol sulfurtransferase
- EC 2.8.1.4: tRNA uracil 4-sulfurtransferase
- EC 2.8.1.5: Thiosulfate—dithiol sulfurtransferase
- EC 2.8.1.6: Biotin synthase
- EC 2.8.1.7: Cysteine desulfurase
- EC 2.8.1.8: Lipoyl synthase
- EC 2.8.1.9: Molybdenum cofactor sulfurtransferase
- EC 2.8.1.10: Thiazole synthase
- EC 2.8.1.11: Molybdopterin synthase sulfurtransferase
- EC 2.8.1.12: Molybdopterin synthase
- EC 2.8.1.13: tRNA-uridine 2-sulfurtransferase
- EC 2.8.1.14: tRNA-5-taurinomethyluridine 2-sulfurtransferase
- EC 2.8.1.15: tRNA-5-methyluridine(54) 2-sulfurtransferase
Category:EC 2.9 (transfer selenium-containing groups)
- EC 2.9.1.1: L-seryl-tRNA(Sec) selenium transferase
- EC 2.9.1.2: O-phospho-L-seryl-tRNA(Sec):L-selenocysteinyl-tRNA synthase
Category:Hydrolases (EC 3) (Hydrolase)
Category:EC 3.1 (act on ester bonds)
- Nuclease
- Endonuclease
- Exonuclease
- Category:EC 3.1.1
- Category:EC 3.1.2
- Category:EC 3.1.3
- Category:EC 3.1.4
- Category:EC 3.1.21
- Restriction enzyme Type 1 (EC 3.1.21.3)
- Restriction enzyme Type 2 (EC 3.1.21.4)
- Restriction enzyme Type 3 (EC 3.1.21.5)
- Restriction enzyme Type 4 (?)
- Deoxyribonuclease I (EC 3.1.21.1)
- Category:EC 3.1.26
- Category:EC 3.1.27
Category:EC 3.2 (act on sugars - glycosylases)
Function and clinical importance of some enzymes in category 3.2.1
Amylase
Function: Amylase is an enzyme that is responsible for the breaking of the bonds in starches, polysaccharides, and complex carbohydrates to be turned into simple sugars that will be easier to absorb.
Clinical Significance: Amylase also has medical history in the use of Pancreatic Enzyme Replacement Therapy (PERT). One of the components is Sollpura (liprotamase), which help in the breakdown of saccharides into simple sugars.
Lysozyme
Function: An enzyme that is produced by animals that forms part of the innate immune system and is abundant in the secretions of saliva, human milk, tears, and mucus. It functions as an antimicrobial agent by splitting the peptidoglycan component of bacterial cell walls, which then leads to cell death.
Clinical Significance: Toxic levels of blood are caused by the excessive production of lysozyme's by cancer cells. Lysozyme's have also been associated with Bronchopulmonary dysplasia (BPD) in newborns and is a key factor in providing the immunology of infants during breast feeding.
Sucrase
Function: Sucrase is a stomachs related protein that mobilizes hydrolysis to convert sucrose into glucose and fructose.
Clinical Significance: Low amounts of Sucrose also known as Sucrose intolerance happens when sucrose isn't being discharged in the small digestive tract. A result of this is extra gas.
Lactase
Function: lactase is located in the small digestives system of people and other creatures such as mammals. Lactase is the bases of the total absorption of milk.
Clinical Significance: People who are lactose intolerant have medicine that can help with the digestion. When you are lactose intolerant you might experience gas, bloating, and pain along with other symptoms regarding your digestive system.
Category:EC 3.3 (act on ether bonds)
- Category:EC 3.3
- Adenosylmethionine hydrolase
- S-adenosyl-L-homocysteine hydrolase
- Alkenylglycerophosphocholine hydrolase
- Alkenylglycerophosphoethanolamine hydrolase
- Cholesterol-5,6-oxide hydrolase
- Hepoxilin-epoxide hydrolase
- Isochorismatase
- Leukotriene-A4 hydrolase
- Limonene-1,2-epoxide hydrolase
- Microsomal epoxide hydrolase
- Trans-epoxysuccinate hydrolase
Category:EC 3.4 (act on peptide bonds - Peptidase)
- Category:EC 3.4.11
- Category:EC 3.4.15
- Category:EC 3.4.21
- Serine protease
- Chymotrypsin (EC 3.4.21.1)
- Trypsin (EC 3.4.21.4)
- Thrombin (EC 3.4.21.5)
- Factor X (EC 3.4.21.6)
- Plasmin (EC 3.4.21.7)
- Acrosin (EC 3.4.21.10)
- Factor VII (EC 3.4.21.21)
- Factor IX (EC 3.4.21.22)
- Prolyl oligopeptidase (EC 3.4.21.26)
- Factor XI (EC 3.4.21.27)
- Elastase (EC 3.4.21.37)
- Factor XII (EC 3.4.21.38)
- Proteinase K (EC 3.4.21.64)
- Tissue plasminogen activator (EC 3.4.21.68)
- Protein C (EC 3.4.21.69)
- Category:EC 3.4.22
- Category:EC 3.4.23
- Category:EC 3.4.24
- Category:EC 3.4.25
Category:EC 3.5 (act on carbon–nitrogen bonds, other than peptide bonds)
- Category:EC 3.5.1 (In linear amides)
- Category:EC 3.5.2 (In cyclic amides)
- Category:EC 3.5.3 (In linear amidines)
- Category:EC 3.5.4 (In cyclic amidines)
- Category:EC 3.5.5 (In nitriles)
Category:EC 3.6 (act on acid anhydrides)
Category:EC 3.7 (act on carbon–carbon bonds)
Category:EC 3.8 (act on halide bonds)
- EC 3.8.1.3 Haloacetate dehalogenase
Category:EC 3.9 (act on phosphorus–nitrogen bonds)
- EC 3.9.1.1: Phosphoamidase
- EC 3.9.1.2: Protein arginine phosphatase
- EC 3.9.1.3: Phosphohistidine phosphatase
Category:EC 3.10 (act on sulfur–nitrogen bonds)
Category:EC 3.11 (act on carbon–phosphorus bonds)
- EC 3.11.1.1: Phosphonoacetaldehyde hydrolase
- EC 3.11.1.2: Phosphonoacetate hydrolase
- EC 3.11.1.3: Phosphonopyruvate hydrolase
Category:EC 3.12 (act on sulfur–sulfur bonds)
Category:EC 3.13 (act on carbon–sulfur bonds)
- EC 3.13.1.1: UDP-sulfoquinovose synthase
- EC 3.13.1.3: 2'-hydroxybiphenyl-2-sulfinate desulfinase
- EC 3.13.1.4: 3-sulfinopropanoyl—CoA desulfinase
- EC 3.13.1.5: Carbon disulfide hydrolase
- EC 3.13.1.6: (CysO sulfur-carrier protein)-S-L-cysteine hydrolase
- EC 3.13.1.7: Carbonyl sulfide hydrolase
- EC 3.13.1.8: S-adenosyl-L-methionine hydrolase (adenosine-forming)
Category:Lyases (EC 4) (Lyase)
Category:EC 4.1 (carbon–carbon lyases)
Category:EC 4.2 (carbon–oxygen lyases)
Category:EC 4.3 (carbon–nitrogen lyases)
Category:EC 4.4 (carbon–sulfur lyases)
Category:EC 4.5 (carbon–halide lyases)
Category:EC 4.6 (phosphorus–oxygen lyases)
Category:Isomerases (EC 5) (Isomerase)
Category:EC 5.1 (racemases and epimerases)
- Category:EC 5.1.1
- Amino-acid racemase: Phenylalanine racemase (ATP-hydrolysing)
- Serine racemase
- Category:EC 5.1.2
- Mandelate racemase
- Category:EC 5.1.3
- UDP-glucose 4-epimerase
- Category:EC 5.1.99
- Methylmalonyl CoA epimerase
Category:EC 5.2 (cis-trans-isomerases)
- Category:EC 5.2
- FKBP: FKBP1A
- FKBP1B
- FKBP2
- FKBP3
- FKBP4
- FKBP5
- FKBP6
- FKBP8
- FKBP9
- FKBP10
- FKBPL
- Cyclophilin
- Parvulin
- Prolyl isomerase
- 2-chloro-4-carboxymethylenebut-2-en-1,4-olide isomerase
- Beta-carotene isomerase
- Farnesol 2-isomerase
- Furylfuramide isomerase
- Linoleate isomerase
- Maleate isomerase
- Maleylacetoacetate isomerase
- Maleylpyruvate isomerase
- Parvulin
- Photoisomerase
- Prolycopene isomerase
- Prolyl isomerase
- Retinal isomerase
- Retinol isomerase
- Zeta-carotene isomerase
Category:EC 5.3 (intramolecular oxidoreductases)
Category:EC 5.4 (intramolecular transferases -- mutases)
Category:EC 5.5 (intramolecular lyases)
Category:EC 5.99 (other isomerases)
- Category:EC 5.99.1
- Topoisomerase (type I: EC 5.99.1.2, type II: EC 5.99.1.3)
Category:Ligases (EC 6) (Ligase)
Category:EC 6.1 (form carbon–oxygen bonds)
6-carboxytetrahydropterin synthase
Category:EC 6.2 (form carbon–sulfur bonds)
- EC 6.2.1.1: Acetate—CoA ligase
- EC 6.2.1.2: Medium-chain acyl—CoA ligase
- EC 6.2.1.3: Long-chain-fatty-acid—CoA ligase
- EC 6.2.1.4: Succinate—CoA ligase (GDP-forming)
- EC 6.2.1.5: Succinate—CoA ligase (ADP-forming)
- EC 6.2.1.6: Glutarate—CoA ligase
- EC 6.2.1.7: Cholate—CoA ligase
- EC 6.2.1.8: Oxalate—CoA ligase
- EC 6.2.1.9: Malate—CoA ligase
- EC 6.2.1.10: Acid—CoA ligase (GDP-forming)
- EC 6.2.1.11: Biotin—CoA ligase
- EC 6.2.1.12: 4-coumarate—CoA ligase
- EC 6.2.1.13: Acetate—CoA ligase (ADP-forming)
- EC 6.2.1.14: 6-carboxyhexanoate—CoA ligase
- EC 6.2.1.15: Arachidonate—CoA ligase
- EC 6.2.1.16: Acetoacetate—CoA ligase
- EC 6.2.1.17: Propionate—CoA ligase
- EC 6.2.1.18: Citrate—CoA ligase
- EC 6.2.1.19: Long-chain-fatty-acid-luciferin-component ligase
- EC 6.2.1.20: Long-chain-fatty-acid-(acyl-carrier-protein) ligase
- EC 6.2.1.21: Transferred entry: 6.2.1.30
- EC 6.2.1.22: (citrate (pro-3S)-lyase) ligase
- EC 6.2.1.23: Dicarboxylate—CoA ligase
- EC 6.2.1.24: Phytanate—CoA ligase
- EC 6.2.1.25: Benzoate—CoA ligase
- EC 6.2.1.26: o-succinylbenzoate—CoA ligase
- EC 6.2.1.27: 4-hydroxybenzoate—CoA ligase
- EC 6.2.1.28: 3-alpha,7-alpha-dihydroxy-5-beta-cholestanate—CoA ligase
- EC 6.2.1.29: Transferred entry: 6.2.1.7
- EC 6.2.1.30: Phenylacetate—CoA ligase
- EC 6.2.1.31: 2-furoate—CoA ligase
- EC 6.2.1.32: Anthranilate—CoA ligase
- EC 6.2.1.33: 4-chlorobenzoate—CoA ligase
- EC 6.2.1.34: Trans-feruloyl-CoA synthase
- EC 6.2.1.35: ACP-SH:acetate ligase
- EC 6.2.1.36: 3-hydroxypropionyl-CoA synthase
- EC 6.2.1.37: 3-hydroxybenzoate—CoA ligase
- EC 6.2.1.38: (2,2,3-trimethyl-5-oxocyclopent-3-enyl)acetyl-CoA synthase
- EC 6.2.1.39: (butirosin acyl-carrier protein)—L-glutamate ligase
- EC 6.2.1.40: 4-hydroxybutyrate-CoA ligase
- EC 6.2.1.41: 3-((3aS,4S,7aS)-7a-methyl-1,5-dioxo-octahydro-1H-inden-4-yl)propanoate-CoA ligase
- EC 6.2.1.42: 3-oxocholest-4-en-26-oate-CoA ligase
- EC 6.2.1.43: 2-hydroxy-7-methoxy-5-methyl-1-naphthoate-CoA ligase
- EC 6.2.1.44: 3-(methylthio)propionyl-CoA ligase
- EC 6.2.1.45: E1 ubiquitin-activating enzyme
- EC 6.2.1.46: L-allo-isoleucine--holo-CmaA peptidyl-carrier protein ligase
- EC 6.2.1.47: Medium-chain-fatty-acid-(acyl-carrier-protein) ligase
- EC 6.2.1.48: Carnitine-CoA ligase
- EC 6.2.1.49: Long-chain fatty acid adenylyltransferase FadD28
- EC 6.2.1.50: 4-hydroxybenzoate adenylyltransferase FadD22
- EC 6.2.1.51: 4-hydroxyphenylalkanoate adenylyltransferase FadD29
- EC 6.2.1.52: L-firefly luciferin-CoA ligase
- EC 6.2.1.53: L-proline-L-prolyl-carrier protein ligase
- EC 6.2.1.54: D-alanine-D-alanyl-carrier protein ligase
- EC 6.2.1.55: E1 SAMP-activating enzyme
Category:EC 6.3 (form carbon–nitrogen bonds)
- Glutamine synthetase (EC 6.3.1.2)
- Argininosuccinate synthetase (EC 6.3.4.5)
- CTP synthase (EC 6.3.4.2)