Editing Transferase (section)

==Role==

===EC 2.1: single carbon transferases===
[[Image:ATCase reaction.svg|thumb|Reaction involving aspartate transcarbamylase.]]
EC 2.1 includes enzymes that transfer single-carbon groups. This category consists of transfers of [[methyl]], [[hydroxymethyl]], formyl, carboxy, [[carbamoyl]], and amido groups.<ref>{{cite web|title=EC 2.1.3: Carboxy- and Carbamoyltransferases|url=http://www.chem.qmul.ac.uk/iubmb/enzyme/EC2/1/3/|work=School of Biological & Chemical Sciences at Queen Mary, University of London.|publisher=Nomenclature Committee of the International Union of Biochemistry and Molecular Biology (NC-IUBMB)|access-date=25 November 2013}}</ref> Carbamoyltransferases, as an example, transfer a carbamoyl group from one molecule to another.<ref>{{cite web|title=carbamoyltransferase|url=http://medical-dictionary.thefreedictionary.com/carbamoyltransferase|work=The Free Dictionary|publisher=Farlex, Inc.|access-date=25 November 2013}}</ref> Carbamoyl groups follow the formula NH<sub>2</sub>CO.<ref>{{cite web|title=carbamoyl group (CHEBI:23004)|url=http://www.ebi.ac.uk/chebi/searchId.do?chebiId=CHEBI:23004|work=ChEBI: The database and ontology of Chemical Entities of Biological Interest|publisher=European Molecular Biology Laboratory|access-date=25 November 2013}}</ref> In [[Aspartate carbamoyltransferase|ATCase]] such a transfer is written as [[carbamoyl phosphate]] + L-[[aspartate]] <math>\rightarrow</math> L-carbamoyl aspartate + [[phosphate]].<ref>{{cite journal | vauthors = Reichard P, Hanshoff G | title = Aspartate Carbamyl Transferase from ''Escherichia coli'' | journal = Acta Chemica Scandinavica | year = 1956 | pages = 548–566 | url = http://actachemscand.dk/pdf/acta_vol_10_p0548-0566.pdf | doi = 10.3891/acta.chem.scand.10-0548 | volume=10| doi-access = free }}</ref>

===EC 2.2: aldehyde and ketone transferases===
[[Image:Transaldolase reaction.svg|thumb|The reaction catalyzed by transaldolase]]
Enzymes that transfer aldehyde or ketone groups and included in EC 2.2. This category consists of various transketolases and transaldolases.<ref>{{cite web|title=ENZYME class 2.2.1|url=http://enzyme.expasy.org/EC/2.2.1.-|work=ExPASy: Bioinformatics Resource Portal|publisher=Swiss Institute of Bioinformatics|access-date=25 November 2013}}</ref>  Transaldolase, the namesake of aldehyde transferases, is an important part of the pentose phosphate pathway.<ref>{{cite web|title=Pentose Phosphate Pathway|url=http://www.rpi.edu/dept/bcbp/molbiochem/MBWeb/mb2/part1/pentose.htm|work=Molecular Biochemistry II Notes|publisher=The Biochemistry and Biophysics Program at Renssalaer Polytechnic Institute|access-date=25 November 2013}}</ref>   The reaction it catalyzes consists of a transfer of a dihydroxyacetone functional group to [[glyceraldehyde 3-phosphate]] (also known as G3P).  The reaction is as follows: [[sedoheptulose 7-phosphate]] + glyceraldehyde 3-phosphate <math>\rightleftharpoons</math> [[erythrose 4-phosphate]] + [[fructose 6-phosphate]].<ref>{{cite web|title=EC 2.2.1.2 Transaldolase|url=http://www.ebi.ac.uk/thornton-srv/databases/cgi-bin/enzymes/GetPage.pl?ec_number=2.2.1.2|work=Enzyme Structures Database|publisher=European Molecular Biology Laboratory|access-date=25 November 2013}}</ref>

===EC 2.3: acyl transferases===

Transfer of acyl groups or acyl groups that become alkyl groups during the process of being transferred are key aspects of EC 2.3. Further, this category also differentiates between amino-acyl and non-amino-acyl groups. [[Peptidyl transferase]] is a [[ribozyme]] that facilitates formation of [[peptide bonds]] during [[Translation (biology)|translation]].<ref name="pmid19363482">{{cite journal | vauthors = Voorhees RM, Weixlbaumer A, Loakes D, Kelley AC, Ramakrishnan V | title = Insights into substrate stabilization from snapshots of the peptidyl transferase center of the intact 70S ribosome | journal = Nature Structural & Molecular Biology | volume = 16 | issue = 5 | pages = 528–33 | date = May 2009 | pmid = 19363482 | pmc = 2679717 | doi = 10.1038/nsmb.1577 }}</ref>  As an aminoacyltransferase, it catalyzes the transfer of a peptide to an [[aminoacyl-tRNA]], following this reaction: peptidyl-tRNA<sub>A</sub> + aminoacyl-tRNA<sub>B</sub> <math>\rightleftharpoons</math> tRNA<sub>A</sub> + peptidyl aminoacyl-tRNA<sub>B</sub>.<ref>{{cite web | title = ENZYME entry: EC 2.3.2.12 | url = http://enzyme.expasy.org/EC/2.3.2.12 | work = ExPASy: Bioinformatics Resource Portal|publisher=Swiss Institute of Bioinformatics|access-date=26 November 2013}}</ref>

===EC 2.4: glycosyl, hexosyl, and pentosyl transferases===

EC 2.4 includes enzymes that transfer [[glycosyl]] groups, as well as those that transfer hexose and pentose. [[Glycosyltransferase]] is a subcategory of EC 2.4 transferases that is involved in [[biosynthesis]] of [[disaccharides]] and [[polysaccharides]] through transfer of [[monosaccharides]] to other molecules.<ref>{{cite web|title=Keyword Glycosyltransferase|url=https://www.uniprot.org/keywords/KW-0328|work=UniProt|publisher=UniProt Consortium|access-date=26 November 2013}}</ref>  An example of a prominent glycosyltransferase is [[lactose synthase]] which is a dimer possessing two [[protein subunit]]s.  Its primary action is to produce [[lactose]] from [[glucose]] and UDP-galactose.<ref name="pmid5440844">{{cite journal | vauthors = Fitzgerald DK, Brodbeck U, Kiyosawa I, Mawal R, Colvin B, Ebner KE | title = Alpha-lactalbumin and the lactose synthetase reaction | journal = The Journal of Biological Chemistry | volume = 245 | issue = 8 | pages = 2103–8 | date = Apr 1970 | doi = 10.1016/S0021-9258(18)63212-0 | pmid = 5440844 | url = http://www.jbc.org/content/245/8/2103.long | doi-access = free }}</ref> This occurs via the following pathway: UDP-β-D-galactose + D-glucose <math>\rightleftharpoons</math> [[Uridine diphosphate|UDP]] + lactose.<ref>{{cite web|title=ENZYME entry: EC 2.4.1.22|url=http://enzyme.expasy.org/EC/2.4.1.22|work=ExPASy: Bioinformatics Resource Portal|publisher=Swiss Institute of Bioinformatics|access-date=26 November 2013}}</ref>

===EC 2.5: alkyl and aryl transferases===
EC 2.5 relates to enzymes that transfer alkyl or aryl groups, but does not include methyl groups.  This is in contrast to functional groups that become alkyl groups when transferred, as those are included in EC 2.3. EC 2.5 currently only possesses one sub-class: Alkyl and aryl transferases.<ref>{{cite web|title=EC 2.5|url=http://www.ebi.ac.uk/intenz/query?cmd=SearchEC&ec=2.5|work=IntEnz|publisher=European Molecular Biology Laboratory|access-date=26 November 2013}}</ref> [[Cysteine synthase]], for example, catalyzes the formation of acetic acids and [[cysteine]] from O<sub>3</sub>-acetyl-L-serine and [[hydrogen sulfide]]: O<sub>3</sub>-acetyl-L-serine + H<sub>2</sub>S <math>\rightleftharpoons</math> L-cysteine + acetate.<ref name="pmid24260346">{{cite journal | vauthors = Qabazard B, Ahmed S, Li L, Arlt VM, Moore PK, Stürzenbaum SR | title = C. elegans aging is modulated by hydrogen sulfide and the sulfhydrylase/cysteine synthase cysl-2 | journal = PLOS ONE | volume = 8 | issue = 11 | pages = e80135 | year = 2013 | pmid = 24260346 | pmc = 3832670 | doi = 10.1371/journal.pone.0080135 | bibcode = 2013PLoSO...880135Q | doi-access = free }}</ref>

===EC 2.6: nitrogenous transferases===
[[Image:Aspartate aminotransferase reaction.png|thumb|450px|Aspartate aminotransferase can act on several different amino acids]]
The grouping consistent with transfer of [[nitrogenous]] groups is EC 2.6.  This includes enzymes like [[transaminase]] (also known as "aminotransferase"), and a very small number of [[oximinotransferase]]s and other nitrogen group transferring enzymes. EC 2.6 previously included [[amidinotransferase]] but it has since been reclassified as a subcategory of EC 2.1 (single-carbon transferring enzymes).<ref>{{cite web|title=EC 2.6.2|url=http://www.chem.qmul.ac.uk/iubmb/enzyme/EC2/6/2/|work=IUBMB Enzyme Nomenclatur|publisher=Nomenclature Committee of the International Union of Biochemistry and Molecular Biology (NC-IUBMB)|access-date=28 November 2013}}</ref> In the case of [[aspartate transaminase]], which can act on [[tyrosine]], [[phenylalanine]], and [[tryptophan]], it reversibly transfers an [[amino]] group from one molecule to the other.<ref name="pmid6143829">{{cite journal | vauthors = Kirsch JF, Eichele G, Ford GC, Vincent MG, Jansonius JN, Gehring H, Christen P | title = Mechanism of action of aspartate aminotransferase proposed on the basis of its spatial structure | journal = Journal of Molecular Biology | volume = 174 | issue = 3 | pages = 497–525 | date = Apr 1984 | pmid = 6143829 | doi = 10.1016/0022-2836(84)90333-4 }}</ref>

The reaction, for example, follows the following order: L-aspartate +2-oxoglutarate <math>\rightleftharpoons</math> oxaloacetate + L-glutamate.<ref>{{cite web | title = <nowiki>Enzyme entry:2.6.1.1</nowiki> | url = http://enzyme.expasy.org/EC/2.6.1.1 | work = ExPASy: Bioinformatics Resource Portal | publisher = Swiss Institute of Bioinformatics | access-date = 28 November 2013 }}</ref>

===EC 2.7: phosphorus transferases===

While EC 2.7 includes enzymes that transfer [[phosphorus]]-containing groups, it also includes nuclotidyl transferases as well.<ref>{{cite web|title=EC 2.7|url=http://www.chem.qmul.ac.uk/iubmb/enzyme/EC2/7/|work=School of Biological & Chemical Sciences at Queen Mary, University of London|publisher=Nomenclature Committee of the International Union of Biochemistry and Molecular Biology (NC-IUBMB)|access-date=4 December 2013}}</ref> Sub-category [[phosphotransferase]] is divided up in categories based on the type of group that accepts the transfer.<ref name="EC2 Intro" /> Groups that are classified as phosphate acceptors include: alcohols, carboxy groups, nitrogenous groups, and phosphate groups.<ref name="EC2 List" /> Further constituents of this subclass of transferases are various kinases. A prominent kinase is [[cyclin-dependent kinase]] (CDK), which comprises a sub-family of [[protein kinase]]s. As their name implies, CDKs are heavily dependent on specific [[cyclin]] molecules for [[Bioactivation|activation]].<ref name="pmid8550604">{{cite journal | vauthors = Yee A, Wu L, Liu L, Kobayashi R, Xiong Y, Hall FL | title = Biochemical characterization of the human cyclin-dependent protein kinase activating kinase. Identification of p35 as a novel regulatory subunit | journal = The Journal of Biological Chemistry | volume = 271 | issue = 1 | pages = 471–7 | date = Jan 1996 | pmid = 8550604 | doi =  10.1074/jbc.271.1.471| s2cid = 20348897 | doi-access = free }}</ref>  Once combined, the CDK-cyclin complex is capable of enacting its function within the cell cycle.<ref>{{cite book|last=Lewis|first=Ricki | name-list-style = vanc |title=Human genetics : concepts and applications|url=https://archive.org/details/humangeneticsthe00lewi|url-access=limited|year=2008|publisher=McGraw-Hill/Higher Education|location=Boston|isbn=978-0-07-299539-8|page=[https://archive.org/details/humangeneticsthe00lewi/page/n487 32]|edition=8th}}</ref>

The reaction catalyzed by CDK is as follows: ATP + a target protein <math>\rightarrow</math> ADP + a phosphoprotein.<ref>{{cite web|title=ENZYME Entry: EC 2.7.11.22|url=http://enzyme.expasy.org/EC/2.7.11.22|work=ExPASy: Bioinformatics Resource Portal|publisher=Swiss Institute of Bioinformatics|access-date=4 December 2013}}</ref>

===EC 2.8: sulfur transferases===

[[File:PDB 1aqy EBI.jpg|thumb|left|Ribbon diagram of a variant structure of estrogen sulfotransferase (PDB 1aqy EBI)<ref>{{cite web|title=1aqy Summary|url=http://www.ebi.ac.uk/pdbe-srv/view/entry/1aqy/summary.html|work=Protein Data Bank in Europe Bringing Structure to Biology|publisher=The European Bioinformatics Institute|access-date=11 December 2013}}</ref>]]

Transfer of sulfur-containing groups is covered by EC 2.8 and is subdivided into the subcategories of sulfurtransferases, sulfotransferases, and CoA-transferases, as well as enzymes that transfer alkylthio groups.<ref>{{cite web|title=EC 2.8 Transferring Sulfur-Containing Groups|url=http://www.chem.qmul.ac.uk/iubmb/enzyme/EC2/0801p.html|work=School of Biological & Chemical Sciences at Queen Mary, University of London|publisher=Nomenclature Committee of the International Union of Biochemistry and Molecular Biology (NC-IUBMB).|access-date=11 December 2013}}</ref> A specific group of sulfotransferases are those that use [[3'-Phosphoadenosine-5'-phosphosulfate|PAPS]] as a sulfate group donor.<ref>{{cite journal | vauthors = Negishi M, Pedersen LG, Petrotchenko E, Shevtsov S, Gorokhov A, Kakuta Y, Pedersen LC | title = Structure and function of sulfotransferases | journal = Archives of Biochemistry and Biophysics | volume = 390 | issue = 2 | pages = 149–57 | date = Jun 2001 | pmid = 11396917 | doi = 10.1006/abbi.2001.2368 | url = https://zenodo.org/record/1229406 }}</ref> Within this group is [[alcohol sulfotransferase]] which has a broad targeting capacity.<ref>{{cite web|title=EC 2.8 Transferring Sulfur-Containing Groups|url=http://www.chem.qmul.ac.uk/iubmb/enzyme/EC2/0801p.html#0202|work=School of Biological & Chemical Sciences at Queen Mary, University of London.|publisher=Nomenclature Committee of the International Union of Biochemistry and Molecular Biology (NC-IUBMB).|access-date=11 December 2013}}</ref> Due to this, alcohol sulfotransferase is also known by several other names including "hydroxysteroid sulfotransferase," "steroid sulfokinase," and "estrogen sulfotransferase."<ref>{{cite web|title=Enzyme 2.8.2.2|url=http://www.genome.jp/dbget-bin/www_bget?ec:2.8.2.2|work=Kegg: DBGET|publisher=Kyoto University Bioinformatics Center|access-date=11 December 2013}}</ref> Decreases in its activity has been linked to human liver disease.<ref>{{cite journal | vauthors = Ou Z, Shi X, Gilroy RK, Kirisci L, Romkes M, Lynch C, Wang H, Xu M, Jiang M, Ren S, Gramignoli R, Strom SC, Huang M, Xie W | title = Regulation of the human hydroxysteroid sulfotransferase (SULT2A1) by RORα and RORγ and its potential relevance to human liver diseases | journal = Molecular Endocrinology | volume = 27 | issue = 1 | pages = 106–15 | date = Jan 2013 | pmid = 23211525 | doi = 10.1210/me.2012-1145 | pmc=3545217}}</ref> This transferase acts via the following reaction: 3'-phosphoadenylyl sulfate + an alcohol <math>\rightleftharpoons</math> adenosine 3',5'bisphosphate + an alkyl sulfate.<ref>{{cite journal | vauthors = Sekura RD, Marcus CJ, Lyon ES, Jakoby WB | title = Assay of sulfotransferases | journal = Analytical Biochemistry | volume = 95 | issue = 1 | pages = 82–6 | date = May 1979 | pmid = 495970 | doi = 10.1016/0003-2697(79)90188-x }}</ref>

===EC 2.9: selenium transferases===

EC 2.9 includes enzymes that transfer [[selenium]]-containing groups.<ref>{{cite web|title=EC 2.9.1|url=http://www.chem.qmul.ac.uk/iubmb/enzyme/EC2/9/1/|work=School of Biological & Chemical Sciences at Queen Mary, University of London|publisher=Nomenclature Committee of the International Union of Biochemistry and Molecular Biology (NC-IUBMB)|access-date=11 December 2013}}</ref> This category only contains two transferases, and thus is one of the smallest categories of transferase. Selenocysteine synthase, which was first added to the classification system in 1999, converts seryl-tRNA(Sec UCA) into selenocysteyl-tRNA(Sec UCA).<ref>{{cite journal | vauthors = Forchhammer K, Böck A | title = Selenocysteine synthase from Escherichia coli. Analysis of the reaction sequence | journal = The Journal of Biological Chemistry | volume = 266 | issue = 10 | pages = 6324–8 | date = Apr 1991 | doi = 10.1016/S0021-9258(18)38121-3 | pmid = 2007585 | doi-access = free }}</ref>

===EC 2.10: metal transferases===

The category of EC 2.10 includes enzymes that transfer [[molybdenum]] or [[tungsten]]-containing groups. However, as of 2011, only one enzyme has been added: [[molybdopterin molybdotransferase]].<ref>{{cite web|title=EC 2.10.1|url=http://www.chem.qmul.ac.uk/iubmb/enzyme/EC2/10/1/|work=School of Biological & Chemical Sciences at Queen Mary, University of London.|publisher=Nomenclature Committee of the International Union of Biochemistry and Molecular Biology (NC-IUBMB)|access-date=11 December 2013}}</ref> This enzyme is a component of MoCo biosynthesis in ''Escherichia coli''.<ref>{{cite journal | vauthors = Nichols JD, Xiang S, Schindelin H, Rajagopalan KV | title = Mutational analysis of Escherichia coli MoeA: two functional activities map to the active site cleft | journal = Biochemistry | volume = 46 | issue = 1 | pages = 78–86 | date = Jan 2007 | pmid = 17198377 | doi = 10.1021/bi061551q | pmc=1868504}}</ref>  The reaction it catalyzes is as follows: adenylyl-[[molybdopterin]] + [[molybdate]] <math>\rightarrow</math> molybdenum cofactor + AMP.<ref>{{cite book| editor-first1 = Gerhard | editor-last1 = Michal | editor-first2 = Dietmar | editor-last2 = Schomburg | title=Biochemical Pathways: an Atlas of Biochemistry and Molecular Biology | year = 2010 | publisher = Wiley-Blackwell | location = Oxford | isbn = 9780470146842 | page = 140 | edition = 2nd | doi = 10.1002/9781118657072.ch3 | chapter = Chapter 3: Metabolism | vauthors = Wünschiers R, Jahn M, Jahn D, Schomburg I, Peifer S, Heinzle E, Burtscher H, Garbe J, Steen A, Schobert M, Oesterhelt D, Wachtveitl J, Chang A }}</ref>