Reviewed, UniProtKB/Swiss-Prot Q9S7B5 (THRC1_ARATH)

Names and origin

Protein names

Recommended name:
    Threonine synthase 1, chloroplastic
    EC=4.2.3.1
Alternative name(s):
    Protein METHIONINE OVER-ACCUMULATOR 2

Gene names

Name:	TS1
Synonyms:	MTO2
Ordered Locus Names:	At4g29840
ORF Names:	F27B13.80

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 › eurosids II › Brassicales › Brassicaceae › Arabidopsis

Protein attributes

Sequence length	526 AA.
Sequence status	Complete.
Sequence processing	The displayed sequence is further processed into a mature form.
Protein existence	Evidence at protein level.

General annotation (Comments)

Catalytic activity	O-phospho-L-homoserine + H2O = L-threonine + phosphate.
Cofactor	Pyridoxal phosphate.
Enzyme regulation	Allosterically activated by S-adenosyl-L-methionine (SAM). Activated by S-adenosyl-L-ethionine, 5'-amino-5'-deoxyadenosine, sinefungin and 5'-deoxy-5-methylthioadenosine. Inhibited by AMP. Ref.5
Pathway	Amino-acid biosynthesis; L-threonine biosynthesis; L-threonine from L-aspartate: step 5/5.
Subunit structure	Homodimer. Ref.5
Subcellular location	Plastid › chloroplast.
Domain	The N-terminal domain (1-77) is essential for regulation by S-adenosyl-L-methionine and AMP, but not for dimerization.
Miscellaneous	Binds 4 S-adenosyl-L-methionine (SAM) molecules per dimer. Although SAM3 and SAM4 have equivalent positions, their interactions with the protein are not identical. SAM3 interacts with Lys-181 and Asn-187 of monomer B, whereas SAM4 interacts only with Lys-181 of monomer A. Much more active than TS2 at physiological concentrations of S-adenosyl-L-methionine (20 µM).
Sequence similarities	Belongs to the serine/threonine dehydratase family.
Biophysicochemical properties	Kinetic parameters: KM=30 µM for O-phospho-L-homoserine (in presence of 100 µM S-adenosyl-L-methionine) KM=120 µM for O-phospho-L-homoserine (in absence of 100 µM S-adenosyl-L-methionine)

Ontologies

Keywords
Biological process	Amino-acid biosynthesis Threonine biosynthesis
Cellular component	Chloroplast Plastid
Domain	Transit peptide
Ligand	Pyridoxal phosphate S-adenosyl-L-methionine
Molecular function	Lyase
Technical term	3D-structure Allosteric enzyme Complete proteome
Gene Ontology (GO)
Biological process	threonine biosynthetic process Inferred from electronic annotation. Source: UniProtKB-KW
Cellular component	chloroplast Inferred from direct assay. Source: TAIR
Molecular function	pyridoxal phosphate binding Inferred from electronic annotation. Source: InterPro threonine synthase activity Ref.8 Inferred from direct assay. Source: TAIR
Complete GO annotation...

Sequence annotation (Features)

Feature key

Position(s)

Length

Description

Graphical view

Feature identifier

Molecule processing

Transit peptide

1 – 40

40

Chloroplast

Chain

41 – 526

486

Threonine synthase 1, chloroplastic

PRO_0000033617

Regions

Region

142 – 144

3

S-adenosyl-L-methionine 1 binding; shared with dimeric partner

Region

165 – 167

3

S-adenosyl-L-methionine 1 binding; shared with dimeric partner

Compositional bias

159 – 162

4

Poly-Asp

Sites

Binding site

172

1

S-adenosyl-L-methionine 2; shared with dimeric partner

Binding site

173

1

S-adenosyl-L-methionine 2; via amide nitrogen and carbonyl oxygen; shared with dimeric partner

Binding site

181

1

S-adenosyl-L-methionine 3; in monomer B

Binding site

181

1

S-adenosyl-L-methionine 4; in monomer A

Binding site

187

1

S-adenosyl-L-methionine 3; in monomer B

Amino acid modifications

Modified residue

203

1

N6-(pyridoxal phosphate)lysine

Experimental info

Mutagenesis

205

1

L → R in mto2-1; causes a strong decrease in the concentration of soluble threonine and over-accumulation of methionine. Ref.6

Sequence conflict

2

1

A → L in AAB04607. Ref.3

Secondary structure

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526

Helix Strand Turn

Details...

Helix

60 – 64

5

Beta strand

81 – 87

7

Beta strand

110 – 115

6

Helix

117 – 121

5

Helix

125 – 133

9

Turn

134 – 137

4

Turn

141 – 144

4

Helix

148 – 153

6

Helix

160 – 162

3

Beta strand

173 – 175

3

Helix

177 – 184

8

Beta strand

187 – 193

7

Helix

204 – 219

16

Beta strand

226 – 229

4

Helix

234 – 246

13

Beta strand

250 – 255

6

Helix

256 – 258

3

Helix

261 – 269

9

Beta strand

273 – 279

7

Helix

281 – 294

14

Beta strand

297 – 299

3

Helix

300 – 302

3

Helix

304 – 311

8

Helix

313 – 321

9

Beta strand

328 – 333

6

Helix

338 – 352

15

Beta strand

355 – 357

3

Beta strand

361 – 367

7

Helix

373 – 378

6

Turn

379 – 383

5

Helix

406 – 414

9

Beta strand

418 – 422

5

Helix

424 – 436

13

Helix

443 – 457

15

Beta strand

467 – 471

5

Helix

475 – 478

4

Helix

479 – 486

8

Beta strand

502 – 506

5

Helix

508 – 518

11

Sequences

	Sequence		Length	Mass (Da)
	Q9S7B5-1 [UniParc]. Last modified May 1, 2000. Version 1. Checksum: B27787A57B882AD0	FASTA	526	57,777
	10 20 30 40 50 60 MASSCLFNAS VSSLNPKQDP IRRHRSTSLL RHRPVVISCT ADGNNIKAPI ETAVKPPHRT 70 80 90 100 110 120 EDNIRDEARR NRSNAVNPFS AKYVPFNAAP GSTESYSLDE IVYRSRSGGL LDVEHDMEAL 130 140 150 160 170 180 KRFDGAYWRD LFDSRVGKST WPYGSGVWSK KEWVLPEIDD DDIVSAFEGN SNLFWAERFG 190 200 210 220 230 240 KQFLGMNDLW VKHCGISHTG SFKDLGMTVL VSQVNRLRKM KRPVVGVGCA STGDTSAALS 250 260 270 280 290 300 AYCASAGIPS IVFLPANKIS MAQLVQPIAN GAFVLSIDTD FDGCMKLIRE ITAELPIYLA 310 320 330 340 350 360 NSLNSLRLEG QKTAAIEILQ QFDWQVPDWV IVPGGNLGNI YAFYKGFKMC QELGLVDRIP 370 380 390 400 410 420 RMVCAQAANA NPLYLHYKSG WKDFKPMTAS TTFASAIQIG DPVSIDRAVY ALKKCNGIVE 430 440 450 460 470 480 EATEEELMDA MAQADSTGMF ICPHTGVALT ALFKLRNQGV IAPTDRTVVV STAHGLKFTQ 490 500 510 520 SKIDYHSNAI PDMACRFSNP PVDVKADFGA VMDVLKSYLG SNTLTS

References

	« Hide 'large scale' referencesShow 'large scale' references »
[1]	"Genomic nucleotide sequence of the Arabidopsis threonine synthase gene." Bartlem D., Tamaki Y., Naito S. Plant Gene Register PGR99-108 Cited for: NUCLEOTIDE SEQUENCE [GENOMIC DNA]. Strain: cv. Wassilewskija.
[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]	"Characterization of an Arabidopsis thaliana cDNA encoding an S-adenosylmethionine-sensitive threonine synthase. Threonine synthase from higher plants." Curien G., Dumas R., Ravanel S., Douce R. FEBS Lett. 390:85-90(1996) [PubMed: 8706836] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [MRNA] OF 2-526, CHARACTERIZATION. Strain: cv. Columbia.
[4]	"Allosteric activation of Arabidopsis threonine synthase by S-adenosylmethionine." Curien G., Job D., Douce R., Dumas R. Biochemistry 37:13212-13221(1998) [PubMed: 9748328] [Abstract] Cited for: CHARACTERIZATION.
[5]	"Characterization of recombinant Arabidopsis thaliana threonine synthase." Laber B., Maurer W., Hanke C., Graefe S., Ehlert S., Messerschmidt A., Clausen T. Eur. J. Biochem. 263:212-221(1999) [PubMed: 10429206] [Abstract] Cited for: BIOPHYSICOCHEMICAL PROPERTIES, ENZYME REGULATION, SUBUNIT, CRYSTALLIZATION.
[6]	"Mutation in the threonine synthase gene results in an over-accumulation of soluble methionine in Arabidopsis." Bartlem D., Lambein I., Okamoto T., Itaya A., Uda Y., Kijima F., Tamaki Y., Nambara E., Naito S. Plant Physiol. 123:101-110(2000) [PubMed: 10806229] [Abstract] Cited for: MUTAGENESIS OF LEU-205.
[7]	"Crystal structure of threonine synthase from Arabidopsis thaliana." Thomazeau K., Curien G., Dumas R., Biou V. Protein Sci. 10:638-648(2001) [PubMed: 11344332] [Abstract] Cited for: X-RAY CRYSTALLOGRAPHY (2.25 ANGSTROMS) OF 41-526, PYRIDOXAL PHOSPHATE AT LYS-203.
[8]	"Allosteric threonine synthase. Reorganization of the pyridoxal phosphate site upon asymmetric activation through S-adenosylmethionine binding to a novel site." Mas-Droux C., Biou V., Dumas R. J. Biol. Chem. 281:5188-5196(2006) [PubMed: 16319072] [Abstract] Cited for: X-RAY CRYSTALLOGRAPHY (2.6 ANGSTROMS) OF 41-526 IN COMPLEX WITH PYRIDOXAL PHOSPHATE AND S-ADENOSYL-L-METHIONINE.
+	Additional computationally mapped references.

Cross-references

Sequence databases

EMBLGenBankDDBJ

AB027151 Genomic DNA. Translation: BAA77707.1.
AL050352 Genomic DNA. Translation: CAB43659.1.
AL161575 Genomic DNA. Translation: CAB79742.1.
L41666 mRNA. Translation: AAB04607.1.

IPI

IPI00523359.

PIR

T08545.

RefSeq

NP_194713.1.

UniGene

At.23602

3D structure databases

PDBPDBe

Entry	Method	Resolution (Å)	Chain	Positions	PDBsum
1E5X	X-ray	2.25	A/B	41-526	[»]
2C2B	X-ray	2.60	A/B/C/D/E/F	41-526	[»]
2C2G	X-ray	2.61	A/B	41-526	[»]

ModBase

Search...

Protein-protein interaction databases

STRING

Q9S7B5.

Proteomic databases

PRIDE

Q9S7B5.

ProMEX

Q9S7B5.

Genome annotation databases

GeneID

829106.

GenomeReviews

Gene locus AT4G29840 in contig CT486007_GR.

KEGG

ath:AT4G29840.

NMPDR

fig|3702.1.peg.20957.

Organism-specific databases

TAIR

At4g29840.

Enzyme and pathway databases

BRENDA

4.2.3.1. 302.

Gene expression databases

ArrayExpress

Q9S7B5.

Genevestigator

Q9S7B5.

Family and domain databases

InterPro

IPR001926. PyrdxlP-dep_enz_bsu.
IPR000634. Ser/Thr_deHydtase_PyrdxlP-BS.
IPR004450. Thr_synthase.
[Graphical view]

Pfam

PF00291. PALP. 1 hit.
[Graphical view]

TIGRFAMs

TIGR00260. thrC. 1 hit.

PROSITE

PS00165. DEHYDRATASE_SER_THR. 1 hit.
[Graphical view]

ProtoNet

Search...

Entry information

Entry name

THRC1_ARATH

Accession

Primary (citable) accession number: Q9S7B5
Secondary accession number(s): Q39144

Entry history

Integrated into UniProtKB/Swiss-Prot:	January 23, 2002
Last sequence update:	May 1, 2000
Last modified:	October 13, 2009
This is version 84 of the entry and version 1 of the sequence. [Complete history]

Entry status

Reviewed (UniProtKB/Swiss-Prot)

Annotation project

PPAP (Plant Proteome Annotation Project)