Reviewed, UniProtKB/Swiss-Prot P38605 (CAS1_ARATH)

Names and origin

Protein names

Recommended name:
    Cycloartenol synthase
      Short name=AtCYC
    EC=5.4.99.8
Alternative name(s):
    2,3-epoxysqualene--cycloartenol cyclase

Gene names

Name:	CAS1
Synonyms:	CYC
Ordered Locus Names:	At2g07050
ORF Names:	T4E14.16

Organism

Arabidopsis thaliana (Mouse-ear cress) [Complete proteome]

Taxonomic identifier

3702 [NCBI]

Taxonomic lineage

Eukaryota › Viridiplantae › Streptophyta › Embryophyta › Tracheophyta › Spermatophyta › Magnoliophyta › eudicotyledons › core eudicotyledons › rosids › malvids › Brassicales › Brassicaceae › Arabidopsis

Protein attributes

Sequence length	759 AA.
Sequence status	Complete.
Protein existence	Evidence at protein level.

General annotation (Comments)

Function	Converts oxidosqualene to cycloartenol and 1% parkeol. Involved in plastid biogenesis. Essential for the male gametophyte function. Ref.10
Catalytic activity	(S)-2,3-epoxysqualene = cycloartenol.
Tissue specificity	Expressed in roots, stems, leaves, inflorescences and siliques. Ref.9
Disruption phenotype	Albino phenotype leading to lethality. Ref.10
Sequence similarities	Belongs to the terpene cyclase/mutase family. Contains 5 PFTB repeats.

Ontologies

Keywords
Domain	Repeat
Molecular function	Isomerase
Technical term	Complete proteome
Gene Ontology (GO)
Biological process	pentacyclic triterpenoid biosynthetic process Ref.1 Inferred from direct assay. Source: TAIR pollen development Ref.10 Inferred from mutant phenotype. Source: TAIR thylakoid membrane organization Ref.10 Inferred from mutant phenotype. Source: TAIR
Cellular component	vacuole Inferred from direct assay. Source: TAIR
Molecular function	cycloartenol synthase activity Ref.1 Inferred from direct assay. Source: TAIR
Complete GO annotation...

Sequence annotation (Features)

	Feature key	Position(s)	Length	Description	Graphical view	Feature identifier
Molecule processing
	Chain	1 – 759	759	Cycloartenol synthase		PRO_0000072662
Regions
	Repeat	147 – 188	42	PFTB 1
	Repeat	512 – 557	46	PFTB 2
	Repeat	589 – 629	41	PFTB 3
	Repeat	638 – 679	42	PFTB 4
	Repeat	700 – 741	42	PFTB 5
Sites
	Active site	257	1	Proton acceptor Potential
	Active site	483	1	Proton donor Potential
Experimental info
	Mutagenesis	410	1	Y → C: Produces lanosterol instead of cycloartenol. Ref.4 Ref.7 Ref.8
	Mutagenesis	410	1	Y → T: Produces 65% lanosterol, 2% parkeol and 33% 9beta-delta7-lanosterol instead of cycloartenol. Produces 75% lanosterol, 0.6% parkeol and 24% 9beta-delta7-lanosterol instead of cycloartenol; when associated with V-481. Produces 75% lanosterol and 24% 9beta-delta7-lanosterol instead of cycloartenol; when associated with N-477 or Q-477 and V-481. Ref.4 Ref.7 Ref.8
	Mutagenesis	469	1	A → V: Produces lanosterol and achilleol A instead of cycloartenol. Ref.7
	Mutagenesis	477	1	H → N: Produces 88% lanosterol and 12% parkeol instead of cycloartenol. Produces 75% lanosterol and 24% 9beta-delta7-lanosterol instead of cycloartenol; when associated with T-410 and V-481. Ref.7 Ref.8 Ref.6
	Mutagenesis	477	1	H → Q: Produces 22% lanosterol, 73% parkeol and 5% 9beta-delta7-lanosterol instead of cycloartenol. Produces 75% lanosterol and 24% 9beta-delta7-lanosterol instead of cycloartenol; when associated with T-410 and V-481. Ref.7 Ref.8 Ref.6
	Mutagenesis	477	1	H → Y: Produces lanosterol instead of cycloartenol. Ref.7 Ref.8 Ref.6
	Mutagenesis	481	1	I → T: Produces lanosterol and achilleol A instead of cycloartenol. Ref.4 Ref.7 Ref.8
	Mutagenesis	481	1	I → V: Produces 24% lanosterol, 20% parkeol and 56% cycloartenol. Produces 75% lanosterol, 0.6% parkeol and 24% 9beta-delta7-lanosterol instead of cycloartenol; when associated with T-410. Ref.4 Ref.7 Ref.8
	Mutagenesis	532	1	Y → H: Produces lanosterol and achilleol A instead of cycloartenol. Ref.7
	Sequence conflict	501	1	A → E in AAC04931. Ref.1

Sequences

	Sequence		Length	Mass (Da)
	P38605-1 [UniParc]. Last modified June 20, 2002. Version 2. Checksum: DBA75CC57BB1F74D	FASTA	759	86,033
	10 20 30 40 50 60 MWKLKIAEGG SPWLRTTNNH VGRQFWEFDP NLGTPEDLAA VEEARKSFSD NRFVQKHSAD 70 80 90 100 110 120 LLMRLQFSRE NLISPVLPQV KIEDTDDVTE EMVETTLKRG LDFYSTIQAH DGHWPGDYGG 130 140 150 160 170 180 PMFLLPGLII TLSITGALNT VLSEQHKQEM RRYLYNHQNE DGGWGLHIEG PSTMFGSVLN 190 200 210 220 230 240 YVTLRLLGEG PNDGDGDMEK GRDWILNHGG ATNITSWGKM WLSVLGAFEW SGNNPLPPEI 250 260 270 280 290 300 WLLPYFLPIH PGRMWCHCRM VYLPMSYLYG KRFVGPITST VLSLRKELFT VPYHEVNWNE 310 320 330 340 350 360 ARNLCAKEDL YYPHPLVQDI LWASLHKIVE PVLMRWPGAN LREKAIRTAI EHIHYEDENT 370 380 390 400 410 420 RYICIGPVNK VLNMLCCWVE DPNSEAFKLH LPRIHDFLWL AEDGMKMQGY NGSQLWDTGF 430 440 450 460 470 480 AIQAILATNL VEEYGPVLEK AHSFVKNSQV LEDCPGDLNY WYRHISKGAW PFSTADHGWP 490 500 510 520 530 540 ISDCTAEGLK AALLLSKVPK AIVGEPIDAK RLYEAVNVII SLQNADGGLA TYELTRSYPW 550 560 570 580 590 600 LELINPAETF GDIVIDYPYV ECTSAAIQAL ISFRKLYPGH RKKEVDECIE KAVKFIESIQ 610 620 630 640 650 660 AADGSWYGSW AVCFTYGTWF GVKGLVAVGK TLKNSPHVAK ACEFLLSKQQ PSGGWGESYL 670 680 690 700 710 720 SCQDKVYSNL DGNRSHVVNT AWAMLALIGA GQAEVDRKPL HRAARYLINA QMENGDFPQQ 730 740 750 EIMGVFNRNC MITYAAYRNI FPIWALGEYR CQVLLQQGE

References

	« Hide 'large scale' referencesShow 'large scale' references »
[1]	"Isolation of an Arabidopsis thaliana gene encoding cycloartenol synthase by functional expression in a yeast mutant lacking lanosterol synthase by the use of a chromatographic screen." Corey E.J., Matsuda S.P.T., Bartel B. Proc. Natl. Acad. Sci. U.S.A. 90:11628-11632(1993) [PubMed: 7505443] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [MRNA]. Strain: cv. Landsberg erecta.
[2]	"Sequence and analysis of chromosome 2 of the plant Arabidopsis thaliana." Lin X., Kaul S., Rounsley S.D., Shea T.P., Benito M.-I., Town C.D., Fujii C.Y., Mason T.M., Bowman C.L., Barnstead M.E., Feldblyum T.V., Buell C.R., Ketchum K.A., Lee J.J., Ronning C.M., Koo H.L., Moffat K.S., Cronin L.A. , Shen M., Pai G., Van Aken S., Umayam L., Tallon L.J., Gill J.E., Adams M.D., Carrera A.J., Creasy T.H., Goodman H.M., Somerville C.R., Copenhaver G.P., Preuss D., Nierman W.C., White O., Eisen J.A., Salzberg S.L., Fraser C.M., Venter J.C. Nature 402:761-768(1999) [PubMed: 10617197] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA]. Strain: cv. Columbia.
[3]	"Empirical analysis of transcriptional activity in the Arabidopsis genome." Yamada K., Lim J., Dale J.M., Chen H., Shinn P., Palm C.J., Southwick A.M., Wu H.C., Kim C.J., Nguyen M., Pham P.K., Cheuk R.F., Karlin-Newmann G., Liu S.X., Lam B., Sakano H., Wu T., Yu G. , Miranda M., Quach H.L., Tripp M., Chang C.H., Lee J.M., Toriumi M.J., Chan M.M., Tang C.C., Onodera C.S., Deng J.M., Akiyama K., Ansari Y., Arakawa T., Banh J., Banno F., Bowser L., Brooks S.Y., Carninci P., Chao Q., Choy N., Enju A., Goldsmith A.D., Gurjal M., Hansen N.F., Hayashizaki Y., Johnson-Hopson C., Hsuan V.W., Iida K., Karnes M., Khan S., Koesema E., Ishida J., Jiang P.X., Jones T., Kawai J., Kamiya A., Meyers C., Nakajima M., Narusaka M., Seki M., Sakurai T., Satou M., Tamse R., Vaysberg M., Wallender E.K., Wong C., Yamamura Y., Yuan S., Shinozaki K., Davis R.W., Theologis A., Ecker J.R. Science 302:842-846(2003) [PubMed: 14593172] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [LARGE SCALE MRNA]. Strain: cv. Columbia.
[4]	"A tyrosine-to-threonine mutation converts cycloartenol synthase to an oxidosqualene cyclase that forms lanosterol as its major product." Herrera J.B.R., Wilson W.K., Matsuda S.P.T. J. Am. Chem. Soc. 122:6765-6766(2000) Cited for: MUTAGENESIS OF TYR-410 AND ILE-481.
[5]	"Molecular cloning and expression in yeast of 2,3-oxidosqualene-triterpenoid cyclases from Arabidopsis thaliana." Husselstein-Muller T., Schaller H., Benveniste P. Plant Mol. Biol. 45:75-92(2001) [PubMed: 11247608] [Abstract] Cited for: NOMENCLATURE.
[6]	"Directed evolution experiments reveal mutations at cycloartenol synthase residue His477 that dramatically alter catalysis." Segura M.J.R., Lodeiro S., Meyer M.M., Patel A.J., Matsuda S.P.T. Org. Lett. 4:4459-4462(2002) [PubMed: 12465912] [Abstract] Cited for: MUTAGENESIS OF HIS-477.
[7]	"Conversion of a plant oxidosqualene-cycloartenol synthase to an oxidosqualene-lanosterol cyclase by random mutagenesis." Wu T.-K., Griffin J.H. Biochemistry 41:8238-8244(2002) [PubMed: 12081472] [Abstract] Cited for: MUTAGENESIS OF TYR-410; ALA-469; HIS-477; ILE-481 AND TYR-532.
[8]	"Oxidosqualene cyclase second-sphere residues profoundly influence the product profile." Lodeiro S., Segura M.J.R., Stahl M., Schulz-Gasch T., Matsuda S.P.T. ChemBioChem 5:1581-1585(2004) [PubMed: 15515077] [Abstract] Cited for: MUTAGENESIS OF TYR-410; HIS-477 AND ILE-481.
[9]	"Lanosterol synthase in dicotyledonous plants." Suzuki M., Xiang T., Ohyama K., Seki H., Saito K., Muranaka T., Hayashi H., Katsube Y., Kushiro T., Shibuya M., Ebizuka Y. Plant Cell Physiol. 47:565-571(2006) [PubMed: 16531458] [Abstract] Cited for: TISSUE SPECIFICITY.
[10]	"Allelic mutant series reveal distinct functions for Arabidopsis cycloartenol synthase 1 in cell viability and plastid biogenesis." Babiychuk E., Bouvier-Nave P., Compagnon V., Suzuki M., Muranaka T., Van Montagu M., Kushnir S., Schaller H. Proc. Natl. Acad. Sci. U.S.A. 105:3163-3168(2008) [PubMed: 18287026] [Abstract] Cited for: FUNCTION, DISRUPTION PHENOTYPE.
+	Additional computationally mapped references.

Cross-references

Sequence databases
EMBL GenBank DDBJ	U02555 mRNA. Translation: AAC04931.1. AC005171 Genomic DNA. Translation: AAM15015.1. AY094394 mRNA. Translation: AAM19773.1. BT001118 mRNA. Translation: AAN64509.1.
IPI	IPI00535551.
PIR	A49398. H84481.
RefSeq	NP_178722.1.
UniGene	At.10550 Rra.22051 Rsa.24143
3D structure databases
ModBase	Search...
Protein-protein interaction databases
STRING	P38605.
Proteomic databases
PRIDE	P38605.
Genome annotation databases
GeneID	815275.
GenomeReviews	Gene locus AT2G07050 in contig CT485783_GR.
KEGG	ath:AT2G07050.
NMPDR	fig|3702.1.peg.8204.
Organism-specific databases
TAIR	At2g07050.
Phylogenomic databases
eggNOG	KOG0497.
HOGENOM	HBG750669.
InParanoid	P38605.
OMA	KKEMVRY.
PhylomeDB	P38605.
Enzyme and pathway databases
BioCyc	MetaCyc:AT2G07050-MONOMER.
BRENDA	5.4.99.8. 302.
Gene expression databases
ArrayExpress	P38605.
Genevestigator	P38605.
GermOnline	AT2G07050. Arabidopsis thaliana.
Family and domain databases
InterPro	IPR001330. Prenyltrans. IPR018333. Squalene_cyclase. IPR002365. Terpene_synthase_CS. IPR008930. Terpenoid_cyclase/PrenylTrfase. [Graphical view]
Pfam	PF00432. Prenyltrans. 3 hits. [Graphical view]
TIGRFAMs	TIGR01787. squalene_cyclas. 1 hit.
PROSITE	PS01074. TERPENE_SYNTHASES. 1 hit. [Graphical view]
ProtoNet	Search...

Entry information

Entry name

CAS1_ARATH

Accession

Primary (citable) accession number: P38605
Secondary accession number(s): P92967

Entry history

Integrated into UniProtKB/Swiss-Prot:	October 1, 1994
Last sequence update:	June 20, 2002
Last modified:	February 9, 2010
This is version 78 of the entry and version 2 of the sequence. [Complete history]

Entry status

Reviewed (UniProtKB/Swiss-Prot)

Annotation project

PPAP (Plant Proteome Annotation Project)