Reviewed, UniProtKB/Swiss-Prot P53800 (FDFT_NICBE)

Names and origin

Protein names	Recommended name:     Squalene synthetase       Short name=SQS       Short name=SS     EC=2.5.1.21 Alternative name(s):     Farnesyl-diphosphate farnesyltransferase     FPP:FPP farnesyltransferase
Organism	Nicotiana benthamiana
Taxonomic identifier	4100 [NCBI]
Taxonomic lineage	Eukaryota › Viridiplantae › Streptophyta › Embryophyta › Tracheophyta › Spermatophyta › Magnoliophyta › eudicotyledons › core eudicotyledons › asterids › lamiids › Solanales › Solanaceae › Nicotianoideae › Nicotianeae › Nicotiana

Protein attributes

Sequence length	411 AA.
Sequence status	Complete.
Sequence processing	The displayed sequence is not processed.
Protein existence	Evidence at transcript level.

General annotation (Comments)

Catalytic activity	2 farnesyl diphosphate = diphosphate + presqualene diphosphate. Presqualene diphosphate + NAD(P)H = squalene + diphosphate + NAD(P)+.
Cofactor	Magnesium By similarity.
Pathway	Terpene metabolism; lanosterol biosynthesis; lanosterol from farnesyl diphosphate: step 1/3.
Subcellular location	Endoplasmic reticulum membrane; Multi-pass membrane protein By similarity.
Sequence similarities	Belongs to the phytoene/squalene synthetase family.

Ontologies

Keywords
Biological process	Isoprene biosynthesis
Cellular component	Endoplasmic reticulum Membrane
Domain	Transmembrane
Ligand	Magnesium NADP
Molecular function	Oxidoreductase Transferase
Technical term	Multifunctional enzyme
Gene Ontology (GO)
Biological process	isoprenoid biosynthetic process Inferred from electronic annotation. Source: UniProtKB-KW oxidation reduction Inferred from electronic annotation. Source: UniProtKB-KW
Cellular component	endoplasmic reticulum Inferred from electronic annotation. Source: UniProtKB-KW integral to membrane Inferred from electronic annotation. Source: UniProtKB-SubCell
Molecular function	farnesyl-diphosphate farnesyltransferase activity Inferred from electronic annotation. Source: EC magnesium ion binding Inferred from electronic annotation. Source: UniProtKB-KW oxidoreductase activity Inferred from electronic annotation. Source: UniProtKB-KW
Complete GO annotation...

Sequence annotation (Features)

	Feature key	Position(s)	Length	Description	Graphical view	Feature identifier
Molecule processing
	Chain	1 – 411	411	Squalene synthetase		PRO_0000067456
Regions
	Transmembrane	281 – 301	21	Potential
	Transmembrane	388 – 408	21	Potential

Sequences

	Sequence		Length	Mass (Da)
	P53800-1 [UniParc]. Last modified October 1, 1996. Version 1. Checksum: 5DE209E9BB70A42A	FASTA	411	47,083
	10 20 30 40 50 60 MGSLRAILKN PEDLYPLVKL KLAARHAEKQ IPPSPNWGFC YSMLHKVSRS FALVIQQLPV 70 80 90 100 110 120 ELRDAVCIFY LVLRALDTVE DDTSIPTDVK VPILISFHQH VYDREWHFSC GTKEYKVLMD 130 140 150 160 170 180 QFHHVSTAFL ELRKHYQQAI EDITMRMGAG MAKFICKEVE TTDDYDEYCH YVAGLVGLGL 190 200 210 220 230 240 SKLFHASEKE DLASDSLSNS MGLFLQKTNI IRDYLEDINE VPKCRMFWPR EIWSKYVNKL 250 260 270 280 290 300 EELKYEDNSA KAVQCLNDMV TNALPHVEDC LTYMSALRDP SIFRFCAIPQ VMAIGTLAMC 310 320 330 340 350 360 YDNIEVFRGV VKMRRGLTAK VIDRTRTIAD VYGAFFDFSC MLKSKVNNND PNATKTLKRL 370 380 390 400 410 EVILKTCRDS GTLNKRKSYI IRSEPNYSPV LIVVIFIILA IILAQLSGNR S

References

[1]	"Molecular cloning, in vitro expression and characterization of a plant squalene synthetase cDNA." Hanley K.M., Nicolas O., Donaldson T.B., Smith-Monroy C., Robinson G.W., Hellmann G.M. Plant Mol. Biol. 30:1139-1151(1996) [PubMed: 8704125] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [MRNA].

Cross-references

Sequence databases
EMBLGenBankDDBJ	U46000 mRNA. Translation: AAA87048.1.
PIR	S71771.
3D structure databases
HSSP	HSSP built from PDB template 1EZF based on UniProtKB P37268.
ModBase	Search...
Enzyme and pathway databases
BRENDA	2.5.1.21. 276974.
Family and domain databases
InterPro	IPR002060. Squ/phyt_synthse. IPR006449. Squal_synth. IPR019845. Squalene/phytoene_synthase_CS. IPR008949. Terpenoid_synth. [Graphical view]
Gene3D	G3DSA:1.10.600.10. Terpenoid_synth. 1 hit.
Pfam	PF00494. SQS_PSY. 1 hit. [Graphical view]
TIGRFAMs	TIGR01559. squal_synth. 1 hit.
PROSITE	PS01044. SQUALEN_PHYTOEN_SYN_1. 1 hit. PS01045. SQUALEN_PHYTOEN_SYN_2. 1 hit. [Graphical view]
ProtoNet	Search...

Entry information

Entry name

FDFT_NICBE

Accession

Primary (citable) accession number: P53800

Entry history

Integrated into UniProtKB/Swiss-Prot:	October 1, 1996
Last sequence update:	October 1, 1996
Last modified:	October 13, 2009
This is version 55 of the entry and version 1 of the sequence. [Complete history]

Entry status

Reviewed (UniProtKB/Swiss-Prot)

Annotation project

PPAP (Plant Proteome Annotation Project)