Q8RWE8 (GGAP1_ARATH) Reviewed, UniProtKB/Swiss-Prot

Names and origin

Protein names

Recommended name:
GDP-L-galactose phosphorylase 1
EC=2.7.7.69

Alternative name(s):
Protein VITAMIN C DEFECTIVE 2

Gene names

Name:	VTC2
Ordered Locus Names:	At4g26850
ORF Names:	F10M23.190

Organism

Arabidopsis thaliana (Mouse-ear cress)

Taxonomic identifier

3702 [NCBI]

Taxonomic lineage

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

Protein attributes

Sequence length	442 AA.
Sequence status	Complete.
Protein existence	Evidence at protein level

General annotation (Comments)

Function	Catalyzes a reaction of the Smirnoff-Wheeler pathway, the major route to ascorbate biosynthesis in plants. Acts as a phosphorylase rather than as a transferase. Uses preferentially GDP-L-galactose and GDP-D-glucose as substrates. Lower activity with GDP-L-fucose, very low activity with GDP-D-mannose, and no activity with UDP-D-glucose, UDP-D-galactose or ADP-D-glucose. Highly specific for inorganic phosphate as the guanylyl acceptor. Ref.8 Ref.9 Ref.10 Ref.11
Catalytic activity	GDP-L-galactose + phosphate = alpha-L-galactose 1-phosphate + GDP. Ref.8 Ref.9 Ref.10
Enzyme regulation	Not inhibited by dithiothreitol, N-ethylmaleimide, phenylmethane sulfonyl fluoride, ascorbate, L-galactose and L-galactonolactone.
Pathway	Cofactor biosynthesis; L-ascorbate biosynthesis via GDP-alpha-D-mannose pathway; L-ascorbate from GDP-alpha-D-mannose: step 2/5.
Subunit structure	Interacts with TLP1. Ref.12
Subcellular location	Cytoplasm. Nucleus Ref.13.
Tissue specificity	Expressed in leaves, stems, roots, flowers and siliques. Highest expression in green tissues. Ref.9 Ref.13
Developmental stage	Expressed in all developmental stages. Ref.13
Induction	By jasmonate, ozone and high light. Circadian-regulation, with a peak in expression at the begining of the light cycle. Ref.7 Ref.9 Ref.13
Disruption phenotype	Dwarf. 20% of the wild-type ascorbate level, due to the partial redundancy with VTC5. Double mutants vtc2-vtc5 show growth arrest immediately upon germination and are not viable. Ref.9
Sequence similarities	Belongs to the VTC2 family.
Caution	According to publications, it is related to the galactose-1-phosphate uridylyltransferase type 1 family and histidine triad superfamily (Ref.6). However, such families are not detected by prediction tools such as Pfam or SUPFAM.
Biophysicochemical properties	Kinetic parameters: The kinetic properties described in Ref.9 differ quite substantially from the ones shown here. This might be due to the use of different enzyme activity assays. KM=0.01 mM for GDP-L-galactose Ref.8 Ref.9 KM=0.0044 mM for GDP-D-glucose KM=0.52 mM for GDP-D-mannose KM=2.4 mM for phosphate KM=0.76 mM for phosphate KM=45 mM for L-galactose 1-phosphate KM=29 mM for D-glucose 1-phosphate KM=54 mM for D-mannose 1-phosphate KM=67 mM for D-galactose 1-phosphate pH dependence: Optimum pH is 7.5.
Sequence caution	The sequence AAM34266.1 differs from that shown. Reason: Erroneous gene model prediction. The sequence CAB36531.1 differs from that shown. Reason: Erroneous gene model prediction. The sequence CAB79540.1 differs from that shown. Reason: Erroneous gene model prediction.

Ontologies

Keywords
Biological process	Ascorbate biosynthesis
Cellular component	Cytoplasm Nucleus
Ligand	Nucleotide-binding
Molecular function	Guanine-nucleotide releasing factor Hydrolase Nucleotidyltransferase Transferase
Technical term	Complete proteome Reference proteome
Gene Ontology (GO)
Biological process	L-ascorbic acid biosynthetic process Inferred from mutant phenotype. Source: TAIR defense response by callose deposition in cell wall Inferred from mutant phenotype. Source: TAIR defense response to bacterium Inferred from mutant phenotype. Source: TAIR response to heat Inferred from mutant phenotype. Source: TAIR response to jasmonic acid stimulus Inferred from expression pattern Ref.7. Source: TAIR
Cellular component	cytoplasm Inferred from electronic annotation. Source: UniProtKB-SubCell nucleus Inferred from electronic annotation. Source: UniProtKB-SubCell
Molecular function	GDP-D-glucose phosphorylase activity Inferred from direct assay Ref.11. Source: TAIR GDP-galactose:glucose-1-phosphate guanylyltransferase activity Inferred from direct assay Ref.10. Source: TAIR GDP-galactose:mannose-1-phosphate guanylyltransferase activity Inferred from direct assay Ref.10. Source: TAIR GDP-galactose:myoinositol-1-phosphate guanylyltransferase activity Inferred from direct assay Ref.10. Source: TAIR galactose-1-phosphate guanylyltransferase (GDP) activity Inferred from direct assay Ref.8. Source: TAIR glucose-1-phosphate guanylyltransferase (GDP) activity Inferred from direct assay Ref.8. Source: TAIR guanyl-nucleotide exchange factor activity Inferred from electronic annotation. Source: UniProtKB-KW hydrolase activity Inferred from electronic annotation. Source: UniProtKB-KW mannose-1-phosphate guanylyltransferase (GDP) activity Inferred from direct assay Ref.8. Source: TAIR nucleotide binding Inferred from electronic annotation. Source: UniProtKB-KW quercetin 4'-O-glucosyltransferase activity Inferred from direct assay Ref.11. Source: TAIR
Complete GO annotation...

Binary interactions

With	Entry	#Exp.	IntAct	Notes
TLP1	O64511-2	2	EBI-1578760,EBI-1578748

Sequence annotation (Features)

	Feature key	Position(s)	Length	Description	Graphical view	Feature identifier
Molecule processing
	Chain	1 – 442	442	GDP-L-galactose phosphorylase 1		PRO_0000402541
Sites
	Active site	238	1	Tele-GMP-histidine intermediate Probable
Experimental info
	Mutagenesis	224	1	G → D in vtc2-2; loss of activity; dwarf. Ref.1 Ref.9
	Mutagenesis	238	1	H → N: Strongly reduced activity. Ref.11
	Mutagenesis	290	1	S → F in vtc2-3; strongly reduced ascorbate levels. Ref.1 Ref.9
	Sequence conflict	396	1	G → S in AAL07213. Ref.4

Sequences

	Sequence		Length	Mass (Da)
	Q8RWE8 [UniParc]. Last modified June 1, 2002. Version 1. Checksum: 84C389ED098BBA2D	FASTA	442	48,970
	10 20 30 40 50 60 MLKIKRVPTV VSNYQKDDGA EDPVGCGRNC LGACCLNGAR LPLYACKNLV KSGEKLVISH 70 80 90 100 110 120 EAIEPPVAFL ESLVLGEWED RFQRGLFRYD VTACETKVIP GKYGFVAQLN EGRHLKKRPT 130 140 150 160 170 180 EFRVDKVLQS FDGSKFNFTK VGQEELLFQF EAGEDAQVQF FPCMPIDPEN SPSVVAINVS 190 200 210 220 230 240 PIEYGHVLLI PRVLDCLPQR IDHKSLLLAV HMAAEAANPY FRLGYNSLGA FATINHLHFQ 250 260 270 280 290 300 AYYLAMPFPL EKAPTKKITT TVSGVKISEL LSYPVRSLLF EGGSSMQELS DTVSDCCVCL 310 320 330 340 350 360 QNNNIPFNIL ISDCGRQIFL MPQCYAEKQA LGEVSPEVLE TQVNPAVWEI SGHMVLKRKE 370 380 390 400 410 420 DYEGASEDNA WRLLAEASLS EERFKEVTAL AFEAIGCSNQ EEDLEGTIVH QQNSSGNVNQ 430 440 KSNRTHGGPI TNGTAAECLV LQ

References

	« Hide 'large scale' referencesShow 'large scale' references »
[1]	"Arabidopsis map-based cloning in the post-genome era." Jander G., Norris S.R., Rounsley S.D., Bush D.F., Levin I.M., Last R.L. Plant Physiol. 129:440-450(2002) [PubMed: 12068090] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [GENOMIC DNA], MUTAGENESIS OF GLY-224 AND SER-290.
[2]	"Sequence and analysis of chromosome 4 of the plant Arabidopsis thaliana." Mayer K.F.X., Schueller C., Wambutt R., Murphy G., Volckaert G., Pohl T., Duesterhoeft A., Stiekema W., Entian K.-D., Terryn N., Harris B., Ansorge W., Brandt P., Grivell L.A., Rieger M., Weichselgartner M., de Simone V., Obermaier B. , Mache R., Mueller M., Kreis M., Delseny M., Puigdomenech P., Watson M., Schmidtheini T., Reichert B., Portetelle D., Perez-Alonso M., Boutry M., Bancroft I., Vos P., Hoheisel J., Zimmermann W., Wedler H., Ridley P., Langham S.-A., McCullagh B., Bilham L., Robben J., van der Schueren J., Grymonprez B., Chuang Y.-J., Vandenbussche F., Braeken M., Weltjens I., Voet M., Bastiaens I., Aert R., Defoor E., Weitzenegger T., Bothe G., Ramsperger U., Hilbert H., Braun M., Holzer E., Brandt A., Peters S., van Staveren M., Dirkse W., Mooijman P., Klein Lankhorst R., Rose M., Hauf J., Koetter P., Berneiser S., Hempel S., Feldpausch M., Lamberth S., Van den Daele H., De Keyser A., Buysshaert C., Gielen J., Villarroel R., De Clercq R., van Montagu M., Rogers J., Cronin A., Quail M.A., Bray-Allen S., Clark L., Doggett J., Hall S., Kay M., Lennard N., McLay K., Mayes R., Pettett A., Rajandream M.A., Lyne M., Benes V., Rechmann S., Borkova D., Bloecker H., Scharfe M., Grimm M., Loehnert T.-H., Dose S., de Haan M., Maarse A.C., Schaefer M., Mueller-Auer S., Gabel C., Fuchs M., Fartmann B., Granderath K., Dauner D., Herzl A., Neumann S., Argiriou A., Vitale D., Liguori R., Piravandi E., Massenet O., Quigley F., Clabauld G., Muendlein A., Felber R., Schnabl S., Hiller R., Schmidt W., Lecharny A., Aubourg S., Chefdor F., Cooke R., Berger C., Monfort A., Casacuberta E., Gibbons T., Weber N., Vandenbol M., Bargues M., Terol J., Torres A., Perez-Perez A., Purnelle B., Bent E., Johnson S., Tacon D., Jesse T., Heijnen L., Schwarz S., Scholler P., Heber S., Francs P., Bielke C., Frishman D., Haase D., Lemcke K., Mewes H.-W., Stocker S., Zaccaria P., Bevan M., Wilson R.K., de la Bastide M., Habermann K., Parnell L., Dedhia N., Gnoj L., Schutz K., Huang E., Spiegel L., Sekhon M., Murray J., Sheet P., Cordes M., Abu-Threideh J., Stoneking T., Kalicki J., Graves T., Harmon G., Edwards J., Latreille P., Courtney L., Cloud J., Abbott A., Scott K., Johnson D., Minx P., Bentley D., Fulton B., Miller N., Greco T., Kemp K., Kramer J., Fulton L., Mardis E., Dante M., Pepin K., Hillier L.W., Nelson J., Spieth J., Ryan E., Andrews S., Geisel C., Layman D., Du H., Ali J., Berghoff A., Jones K., Drone K., Cotton M., Joshu C., Antonoiu B., Zidanic M., Strong C., Sun H., Lamar B., Yordan C., Ma P., Zhong J., Preston R., Vil D., Shekher M., Matero A., Shah R., Swaby I.K., O'Shaughnessy A., Rodriguez M., Hoffman J., Till S., Granat S., Shohdy N., Hasegawa A., Hameed A., Lodhi M., Johnson A., Chen E., Marra M.A., Martienssen R., McCombie W.R. Nature 402:769-777(1999) [PubMed: 10617198] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA]. Strain: cv. Columbia.
[3]	The Arabidopsis Information Resource (TAIR) Submitted (APR-2011) to the EMBL/GenBank/DDBJ databases Cited for: GENOME REANNOTATION. Strain: cv. Columbia.
[4]	"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.
[5]	"Large-scale analysis of RIKEN Arabidopsis full-length (RAFL) cDNAs." Totoki Y., Seki M., Ishida J., Nakajima M., Enju A., Morosawa T., Kamiya A., Narusaka M., Shin-i T., Nakagawa M., Sakamoto N., Oishi K., Kohara Y., Kobayashi M., Toyoda A., Sakaki Y., Sakurai T., Iida K. , Akiyama K., Satou M., Toyoda T., Konagaya A., Carninci P., Kawai J., Hayashizaki Y., Shinozaki K. Submitted (JUL-2006) to the EMBL/GenBank/DDBJ databases Cited for: NUCLEOTIDE SEQUENCE [LARGE SCALE MRNA]. Strain: cv. Columbia.
[6]	"Hint, Fhit, and GalT: function, structure, evolution, and mechanism of three branches of the histidine triad superfamily of nucleotide hydrolases and transferases." Brenner C. Biochemistry 41:9003-9014(2002) [PubMed: 12119013] [Abstract] Cited for: IDENTIFICATION.
[7]	"Coordinated activation of metabolic pathways for antioxidants and defence compounds by jasmonates and their roles in stress tolerance in Arabidopsis." Sasaki-Sekimoto Y., Taki N., Obayashi T., Aono M., Matsumoto F., Sakurai N., Suzuki H., Hirai M.Y., Noji M., Saito K., Masuda T., Takamiya K., Shibata D., Ohta H. Plant J. 44:653-668(2005) [PubMed: 16262714] [Abstract] Cited for: INDUCTION BY JASMONATE AND OZONE.
[8]	"Arabidopsis VTC2 encodes a GDP-L-galactose phosphorylase, the last unknown enzyme in the Smirnoff-Wheeler pathway to ascorbic acid in plants." Linster C.L., Gomez T.A., Christensen K.C., Adler L.N., Young B.D., Brenner C., Clarke S.G. J. Biol. Chem. 282:18879-18885(2007) [PubMed: 17462988] [Abstract] Cited for: FUNCTION, CATALYTIC ACTIVITY, BIOPHYSICOCHEMICAL PROPERTIES.
[9]	"Two genes in Arabidopsis thaliana encoding GDP-L-galactose phosphorylase are required for ascorbate biosynthesis and seedling viability." Dowdle J., Ishikawa T., Gatzek S., Rolinski S., Smirnoff N. Plant J. 52:673-689(2007) [PubMed: 17877701] [Abstract] Cited for: FUNCTION, INDUCTION BY LIGHT, MUTAGENESIS OF GLY-224 AND SER-290, CATALYTIC ACTIVITY, BIOPHYSICOCHEMICAL PROPERTIES, TISSUE SPECIFICITY, DISRUPTION PHENOTYPE.
[10]	"The missing step of the L-galactose pathway of ascorbate biosynthesis in plants, an L-galactose guanyltransferase, increases leaf ascorbate content." Laing W.A., Wright M.A., Cooney J., Bulley S.M. Proc. Natl. Acad. Sci. U.S.A. 104:9534-9539(2007) [PubMed: 17485667] [Abstract] Cited for: FUNCTION, CATALYTIC ACTIVITY.
[11]	"A second GDP-L-galactose phosphorylase in arabidopsis en route to vitamin C. Covalent intermediate and substrate requirements for the conserved reaction." Linster C.L., Adler L.N., Webb K., Christensen K.C., Brenner C., Clarke S.G. J. Biol. Chem. 283:18483-18492(2008) [PubMed: 18463094] [Abstract] Cited for: FUNCTION, MUTAGENESIS OF HIS-238.
[12]	"Blue light diminishes interaction of PAS/LOV proteins, putative blue light receptors in Arabidopsis thaliana, with their interacting partners." Ogura Y., Komatsu A., Zikihara K., Nanjo T., Tokutomi S., Wada M., Kiyosue T. J. Plant Res. 121:97-105(2008) [PubMed: 17982713] [Abstract] Cited for: INTERACTION WITH TLP1.
[13]	"An expression analysis of the ascorbate biosynthesis enzyme VTC2." Muller-Moule P. Plant Mol. Biol. 68:31-41(2008) [PubMed: 18516687] [Abstract] Cited for: TISSUE SPECIFICITY, SUBCELLULAR LOCATION, DEVELOPMENTAL STAGE, INDUCTION BY LIGHT.
+	Additional computationally mapped references.

Cross-references

Sequence databases
EMBL GenBank DDBJ	AF508793 Genomic DNA. Translation: AAM34266.1. Sequence problems. AL035440 Genomic DNA. Translation: CAB36531.1. Sequence problems. AL161565 Genomic DNA. Translation: CAB79540.1. Sequence problems. CP002687 Genomic DNA. Translation: AEE85260.1. AY056134 mRNA. Translation: AAL07213.1. AY093138 mRNA. Translation: AAM13137.1. BT006589 mRNA. Translation: AAP31933.1. AK226394 mRNA. Translation: BAE98540.1.
IPI	IPI00541735.
PIR	T04808.
RefSeq	NP_567759.1. NM_118819.2.
UniGene	At.23783. At.74980.
3D structure databases
ProteinModelPortal	Q8RWE8.
ModBase	Search...
Protein-protein interaction databases
IntAct	Q8RWE8. 3 interactions.
STRING	Q8RWE8.
Proteomic databases
PRIDE	Q8RWE8.
Protocols and materials databases
StructuralBiologyKnowledgebase	Search...
Genome annotation databases
EnsemblPlants	AT4G26850.1; AT4G26850.1; AT4G26850.
GeneID	828792.
GenomeReviews	Gene locus AT4G26850 in contig CT486007_GR.
KEGG	ath:AT4G26850.
NMPDR	fig|3702.1.peg.20614.
Organism-specific databases
TAIR	At4g26850.
Phylogenomic databases
HOGENOM	HBG318610.
InParanoid	Q8RWE8.
OMA	GVRVILW.
PhylomeDB	Q8RWE8.
ProtClustDB	PLN03103.
Gene expression databases
Genevestigator	Q8RWE8.
Family and domain databases
KO	K14190.
ProtoNet	Search...

Entry information

Entry name

GGAP1_ARATH

Accession

Primary (citable) accession number: Q8RWE8
Secondary accession number(s): Q8LKQ7, Q940B4, Q9SZ25

Entry history

Integrated into UniProtKB/Swiss-Prot:	November 30, 2010
Last sequence update:	June 1, 2002
Last modified:	December 14, 2011
This is version 46 of the entry and version 1 of the sequence. [Complete history]

Entry status

Reviewed (UniProtKB/Swiss-Prot)

Annotation program

Plant Protein Annotation Program