Ditrans,polycis-polyprenyl diphosphate synthase ((2E,6E)-farnesyl diphosphate specific)

{{Infobox enzyme

| Name = Ditrans,polycis-polyprenyl diphosphate synthase ((2E,6E)-farnesyl diphosphate specific)

| EC_number = 2.5.1.87

| CAS_number =

| GO_code =

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Ditrans,polycis-polyprenyl diphosphate synthase ((2E,6E)-farnesyl diphosphate specific) ({{EC number|2.5.1.87}}, RER2, Rer2p, Rer2p Z-prenyltransferase, Srt1p, Srt2p Z-prenyltransferase, ACPT, dehydrodolichyl diphosphate synthase 1) is an enzyme with systematic name (2E,6E)-farnesyl-diphosphate:isopentenyl-diphosphate cistransferase (adding 10--55 isopentenyl units).{{cite journal | vauthors = Sato M, Fujisaki S, Sato K, Nishimura Y, Nakano A | title = Yeast Saccharomyces cerevisiae has two cis-prenyltransferases with different properties and localizations. Implication for their distinct physiological roles in dolichol synthesis | journal = Genes to Cells | volume = 6 | issue = 6 | pages = 495–506 | date = June 2001 | pmid = 11442630 | doi = 10.1046/j.1365-2443.2001.00438.x | doi-access = free }}{{cite journal | vauthors = Poznański J, Szkopinska A | title = Precise bacterial polyprenol length control fails in Saccharomyces cerevisiae | journal = Biopolymers | volume = 86 | issue = 2 | pages = 155–64 | date = June 2007 | pmid = 17345630 | doi = 10.1002/bip.20715 }}{{cite journal | vauthors = Sato M, Sato K, Nishikawa S, Hirata A, Kato J, Nakano A | title = The yeast RER2 gene, identified by endoplasmic reticulum protein localization mutations, encodes cis-prenyltransferase, a key enzyme in dolichol synthesis | journal = Molecular and Cellular Biology | volume = 19 | issue = 1 | pages = 471–83 | date = January 1999 | pmid = 9858571 | pmc = 83905 | doi = 10.1128/mcb.19.1.471 }}{{cite journal | vauthors = Oh SK, Han KH, Ryu SB, Kang H | title = Molecular cloning, expression, and functional analysis of a cis-prenyltransferase from Arabidopsis thaliana. Implications in rubber biosynthesis | journal = The Journal of Biological Chemistry | volume = 275 | issue = 24 | pages = 18482–8 | date = June 2000 | pmid = 10764783 | doi = 10.1074/jbc.M002000200 | doi-access =free }}{{cite journal | vauthors = Cunillera N, Arró M, Forés O, Manzano D, Ferrer A | title = Characterization of dehydrodolichyl diphosphate synthase of Arabidopsis thaliana, a key enzyme in dolichol biosynthesis | journal = FEBS Letters | volume = 477 | issue = 3 | pages = 170–4 | date = July 2000 | pmid = 10908715 | doi = 10.1016/S0014-5793(00)01798-1 | doi-access = }} This enzyme catalyses the following chemical reaction

: (2E,6E)-farnesyl diphosphate + n isopentenyl diphosphate $\backslash rightleftharpoons$ n diphosphate + ditrans, polycis-polyprenyl diphosphate (n $\backslash rightleftharpoons$ 10--55)

The enzyme is involved in biosynthesis of dolichol (a long-chain polyprenol) with a saturated alpha-isoprene unit.