Entry
Name
squalene synthase;
farnesyltransferase;
presqualene-diphosphate synthase;
presqualene synthase;
squalene synthetase;
farnesyl-diphosphate farnesyltransferase;
SQS
Class
Transferases;
Transferring alkyl or aryl groups, other than methyl groups;
Transferring alkyl or aryl groups, other than methyl groups (only sub-subclass identified to date)
BRITE hierarchy
Sysname
(2E,6E)-farnesyl-diphosphate:(2E,6E)-farnesyl-diphosphate farnesyltransferase
Reaction(IUBMB)
2 (2E,6E)-farnesyl diphosphate + NAD(P)H + H+ = squalene + 2 diphosphate + NAD(P)+ (overall reaction) [RN:
R06223 ];
(1a) 2 (2E,6E)-farnesyl diphosphate = diphosphate + presqualene diphosphate [RN:
R00702 ];
(1b) presqualene diphosphate + NAD(P)H + H+ = squalene + diphosphate + NAD(P)+ [RN:
R02872 ]
Reaction(KEGG)
Substrate
Product
Comment
This microsomal enzyme catalyses the first committed step in the biosynthesis of sterols. The enzyme from yeast requires either Mg2+ or Mn2+ for activity. In the absence of NAD(P)H, presqualene diphosphate (PSPP) is accumulated. When NAD(P)H is present, presqualene diphosphate does not dissociate from the enzyme during the synthesis of squalene from farnesyl diphosphate (FPP) [8]. High concentrations of FPP inhibit the production of squalene but not of PSPP [8].
History
EC 2.5.1.21 created 1976, modified 2005, modified 2012
Pathway
ec00909 Sesquiterpenoid and triterpenoid biosynthesis
ec01110 Biosynthesis of secondary metabolites
Orthology
K00801 farnesyl-diphosphate farnesyltransferase
Genes
CJC : 100405611 100410988(FDFT1)
CJO : 107306801 107312392(FDFT1)
ASN : 102368591 102380768 102385901
AMJ : 102562543 102573401(FDFT1) 109282694
PSS : 102453225(FDFT1) 102453483
CPIC : 101942357(FDFT1) 101942618
CABI : 116815291 116815294
ACS : 100553538 100553739 100560926(fdft1) 100563293 100563486 100563681
SUND : 121916997 121936038 121937029
STOW : 125444834 125444876
XLA : 108717235(fdft1.L) 108718290(fdft1.S)
RTEM : 120935611 120936188 120936189 120936190
BBUF : 120997198 120997199 120997200 120998952
BGAR : 122944545 122944547 122944548 122944549 122944550 122944551 122944552
SANH : 107661354 107671088
CCAR : 109065757 109065791
CAUA : 113068573 113073347 113120553
CGIB : 127938600 127984023 128012062
CIDE : 127501943 127502345
MASI : 127409683 127416322
FCD : 110850303 110850304 110857438 110861147
ATH : AT4G34640(SQS1) AT4G34650(SQS2)
ALY : 110230201 9303181 9305204
CSAT : 104716666 104716668 104721325 104729749 104729750 109124813
EUS : EUTSA_v10025338mg EUTSA_v10025392mg
BRP : 103834400 103836007 103836099 103862364 103862654
BNA : 106353454 106353554 106361022 106371265 106428751 106428793 111208288 111212693 111212694 111214348
BOE : 106301985 106304831 106308593 106324379 106328821 106330848
RSZ : 108819316 108842645 108842646 108849231
CPAP : 110808186 110808189 110808190
PVY : 116130012 116130038 116130072 116134221
MINC : 123214512 123227889
GHI : 107908820 107928014 107928928 107937000
DZI : 111281998 111297181 111308825
EGR : 104415898 104415901 104417873 104428608 104453100 104453372
LJA : Lj3g3v3386550.1(Lj3g3v3386550.1) Lj3g3v3386560.1(Lj3g3v3386560.1)
AHF : 112703107 112736932 112765062 112789149
LANG : 109325850 109344046
PDUL : 117614717 117638854
CMAX : 111484252 111499841
CMOS : 111448190 111451168
CPEP : 111776748 111795790
HBR : 110637585 110644111 110646492
MESC : 110612813 110626763
PALZ : 118039704 118058960
CILL : 122311028 122314026
QSU : 112001025 112030281 112035919
SLY : 100316899(SQS1) 101252241 101258416
SPEN : 107001734 107001821 107008117
SOT : 102580869 102581159(PSS1) 102582345 102582647
SSTN : 125857406 125861810 125866352
CANN : 107840471 107843931 107844779
NTA : 107759374 107760995 107790933(TSS) 107791556 107792297 107799710 107813695
NSY : 104211830 104212796 104220676 104248076
NTO : 104088294 104090848 104111326 104121410
NAU : 109210175 109232373 109233469 109244014
INI : 109161942 109165153 109165155 109165158
ITR : 116023019 116032372 116032549 116033681
SIND : 105169693 105172921
OEU : 111374919 111379472 111380678 111380702 111410086 111412627
SSPL : 121746788 121748033 121751570 121760195 121763316 121787688
APAN : 127251725 127252148 127254083 127254227 127256200 127261999
ECAD : 122606631 122610869
CCAV : 112522476 112525044
SOE : 110793850 110793851 110793852
CQI : 110705161 110705162 110705164 110718883 110718885 110718886
PSOM : 113288764 113289395 113346193
DOSA : Os03t0805100-01(Os03g0805100) Os07t0200700-01(Os07g0200700)
TAES : 123105516 123113831 123123327
LPER : 127292296 127292298
PVIR : 120649394 120688373
PPP : 112280540 112281267 112282546
CVR : CHLNCDRAFT_18492(SQS)
NCS : NCAS_0C00280(NCAS0C00280)
NDI : NDAI_0K00290(NDAI0K00290)
TPF : TPHA_0C04820(TPHA0C04820) TPHA_0I00370(TPHA0I00370)
TBL : TBLA_0D03330(TBLA0D03330)
TDL : TDEL_0B00260(TDEL0B00260)
KAF : KAFR_0L01990(KAFR0L01990)
KNG : KNAG_0K00660(KNAG0K00660)
CAL : CAALFM_C208610WA(ERG9)
NTE : NEUTE1DRAFT67078(NEUTE1DRAFT_67078)
SAPO : SAPIO_CDS6942 SAPIO_CDS7603
BFU : BCIN_06g02400(Bcerg9)
ANG : ANI_1_256104(An12g01890) ANI_1_3012024(An02g11000)
ALUC : AKAW2_10929S(ERG9_1) AKAW2_81142A(ERG9_3)
CIM : CIMG_04821 CIMG_08115
CPW : CPC735_021300 CPC735_070290
URE : UREG_02386 UREG_04164
PBL : PAAG_12679(PAAG_09054)
ZTR : MYCGRDRAFT_65850(ERG9)
ADL : AURDEDRAFT_115501 AURDEDRAFT_135052
ABP : AGABI1DRAFT21221(AGABI1DRAFT_21221)
ABV : AGABI2DRAFT50291(AGABI2DRAFT_50291)
MPR : MPER_08376 MPER_11859
MRR : Moror_1285 Moror_16613
SCM : SCHCO_02603898(SCHCODRAFT_02603898)
SMIN : v1.2.017867.t1(symbB.v1.2.017867.t1)
FCY : FRACYDRAFT_209449(PSY4)
BPM : BURPS1710b_A1762(sqs)
BCED : DM42_3690 DM42_5871
BPSL : WS57_03525 WS57_07100
LIH : L63ED372_01027(crtB_3)
MRM : A7982_03038 A7982_08127
SQZ : FQU76_13590 FQU76_14520
SYY : SYNGTS_2857(sll0513)
SYT : SYNGTI_2856(sll0513)
SYS : SYNPCCN_2855(sll0513)
SYQ : SYNPCCP_2855(sll0513)
ACY : Anacy_0443 Anacy_3489
HLU : LT972_09210 LT972_12210
HALA : Hrd1104_01440 Hrd1104_03360
HALL : LC1Hm_0102(erg9) LC1Hm_4111(fdfT)
NBG : DV706_01600 DV706_15670
» show all
Taxonomy
Reference
Authors
Kuswik-Rabiega G, Rilling HC.
Title
Squalene synthetase. Solubilization and partial purification of squalene synthetase, copurification of presqualene pyrophosphate and squalene synthetase activities.
Journal
J Biol Chem 262:1505-9 (1987)
Reference
Authors
Ericsson J, Appelkvist EL, Thelin A, Chojnacki T, Dallner G.
Title
Isoprenoid biosynthesis in rat liver peroxisomes. Characterization of cis-prenyltransferase and squalene synthetase.
Journal
J Biol Chem 267:18708-14 (1992)
Reference
Authors
Tansey TR, Shechter I.
Title
Structure and regulation of mammalian squalene synthase.
Journal
Reference
Authors
LoGrasso PV, Soltis DA, Boettcher BR.
Title
Overexpression, purification, and kinetic characterization of a carboxyl-terminal-truncated yeast squalene synthetase.
Journal
Reference
Authors
Shechter I, Klinger E, Rucker ML, Engstrom RG, Spirito JA, Islam MA, Boettcher BR, Weinstein DB.
Title
Solubilization, purification, and characterization of a truncated form of rat hepatic squalene synthetase.
Journal
J Biol Chem 267:8628-35 (1992)
Sequence
Reference
Authors
Agnew WS, Popjak G.
Title
Squalene synthetase. Stoichiometry and kinetics of presqualene pyrophosphate and squalene synthesis by yeast microsomes.
Journal
J Biol Chem 253:4566-73 (1978)
Reference
Authors
Pandit J, Danley DE, Schulte GK, Mazzalupo S, Pauly TA, Hayward CM, Hamanaka ES, Thompson JF, Harwood HJ Jr.
Title
Crystal structure of human squalene synthase. A key enzyme in cholesterol biosynthesis.
Journal
Sequence
Reference
Authors
Radisky ES, Poulter CD.
Title
Squalene synthase: steady-state, pre-steady-state, and isotope-trapping studies.
Journal
Other DBs
ExplorEnz - The Enzyme Database: 2.5.1.21
ExPASy - ENZYME nomenclature database: 2.5.1.21