Q9SA18 (AKH1_ARATH) Reviewed, UniProtKB/Swiss-Prot

Names and origin

Protein names

Recommended name:
Bifunctional aspartokinase/homoserine dehydrogenase 1, chloroplastic
Short name=AK-HD 1
Short name=AK-HSDH 1

Alternative name(s):
Beta-aspartyl phosphate homoserine 1

Including the following 2 domains:

1. Aspartokinase
   EC=2.7.2.4
2. Homoserine dehydrogenase
   EC=1.1.1.3

Gene names

Name:	AKHSDH1
Synonyms:	AK-HSDH I
Ordered Locus Names:	At1g31230
ORF Names:	F28K20.19, T19E23.1

Organism

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

Taxonomic identifier

3702 [NCBI]

Taxonomic lineage

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

Protein attributes

Sequence length	911 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	L-homoserine + NAD(P)+ = L-aspartate 4-semialdehyde + NAD(P)H. ATP + L-aspartate = ADP + 4-phospho-L-aspartate.
Enzyme regulation	Inhibition of aspartate kinase activity by threonine and leucine and 3-fold activation by cysteine, isoleucine, valine, serine and alanine at 2.5 mM. Partial inhibition of homoserine dehydrogenase activity by threonine and cysteine (14% of activity remaining at saturation with either amino acid). No synergy between the effectors for both activation or inhibition. Ref.6
Pathway	Amino-acid biosynthesis; L-lysine biosynthesis via DAP pathway; (S)-tetrahydrodipicolinate from L-aspartate: step 1/4. Amino-acid biosynthesis; L-methionine biosynthesis via de novo pathway; L-homoserine from L-aspartate: step 1/3. Amino-acid biosynthesis; L-methionine biosynthesis via de novo pathway; L-homoserine from L-aspartate: step 3/3. Amino-acid biosynthesis; L-threonine biosynthesis; L-threonine from L-aspartate: step 1/5. Amino-acid biosynthesis; L-threonine biosynthesis; L-threonine from L-aspartate: step 3/5.
Subunit structure	Homo- or heterodimer Potential.
Subcellular location	Plastid › chloroplast.
Sequence similarities	In the N-terminal section; belongs to the aspartokinase family. In the C-terminal section; belongs to the homoserine dehydrogenase family. Contains 2 ACT domains.
Biophysicochemical properties	Kinetic parameters: KM=2.6 mM for aspartate for the aspartokinase activity (at pH 8.0, in the presence of 150 mM KCl, 20 mM MgCl2, 200 µM NADPH and 20 mM ATP) Ref.6 KM=2.3 mM for aspartate for the aspartokinase activity (at pH 8.0, in the presence of 150 mM KCl, 20 mM MgCl2, 200 µM NADPH, 20 mM ATP and a saturating concentration of alanine) KM=6.5 mM for ATP for the aspartokinase activity (at pH 8.0, in the presence of 150 mM KCl, 20 mM MgCl2, 200 µM NADPH and 50 mM aspartate) KM=0.48 mM for ATP for the aspartokinase activity (at pH 8.0, in the presence of 150 mM KCl, 20 mM MgCl2, 200 µM NADPH, 50 mM aspartate and a saturating concentration of alanine) KM=290 µM for aspartate semialdehyde for the forward reaction of the homoserine dehydrogenase activity (at pH 8.0, in the presence of 150 mM KCl and 200 µM NADPH)
Sequence caution	The sequence AAF24602.1 differs from that shown. Reason: Erroneous gene model prediction. The sequence CAA50500.2 differs from that shown. Reason: Erroneous gene model prediction.

Ontologies

Keywords
Biological process	Amino-acid biosynthesis Methionine biosynthesis
Cellular component	Chloroplast Plastid
Domain	Repeat Transit peptide
Ligand	ATP-binding NADP Nucleotide-binding
Molecular function	Kinase Oxidoreductase Transferase
Technical term	Complete proteome Multifunctional enzyme Reference proteome
Gene Ontology (GO)
Biological_process	lysine biosynthetic process via diaminopimelate Inferred from electronic annotation. Source: UniProtKB-UniPathway methionine biosynthetic process Inferred from electronic annotation. Source: UniProtKB-KW threonine biosynthetic process Inferred from electronic annotation. Source: UniProtKB-UniPathway
Cellular_component	chloroplast stroma Inferred from direct assay PubMed 18633119PubMed 20061580. Source: TAIR
Molecular_function	ATP binding Inferred from electronic annotation. Source: UniProtKB-KW NADP binding Inferred from electronic annotation. Source: InterPro amino acid binding Inferred from electronic annotation. Source: InterPro aspartate kinase activity Inferred from direct assay Ref.6. Source: TAIR homoserine dehydrogenase activity Inferred from direct assay Ref.6. Source: TAIR
Complete GO annotation...

Sequence annotation (Features)

	Feature key	Position(s)	Length	Description	Graphical view	Feature identifier
Molecule processing
	Transit peptide	1 – 82	82	Chloroplast Potential
	Chain	83 – 911	829	Bifunctional aspartokinase/homoserine dehydrogenase 1, chloroplastic		PRO_0000245844
Regions
	Domain	403 – 471	69	ACT 1
	Domain	487 – 554	68	ACT 2
	Nucleotide binding	559 – 564	6	NADP Potential
	Region	83 – 331	249	Aspartokinase By similarity
	Region	332 – 557	226	Interface By similarity
	Region	558 – 911	354	Homoserine dehydrogenase By similarity
Experimental info
	Sequence conflict	517	1	I → M in BAC43372. Ref.4
	Sequence conflict	900	1	I → F in BAC43372. Ref.4

Sequences

	Sequence		Length	Mass (Da)
	Q9SA18 [UniParc]. Last modified May 1, 2000. Version 1. Checksum: 95A663413B68585F	FASTA	911	99,404
	10 20 30 40 50 60 MPVVSLAKVV TSPAVAGDLA VRVPFIYGKR LVSNRVSFGK LRRRSCIGQC VRSELQSPRV 70 80 90 100 110 120 LGSVTDLALD NSVENGHLPK GDSWAVHKFG GTCVGNSERI KDVAAVVVKD DSERKLVVVS 130 140 150 160 170 180 AMSKVTDMMY DLIHRAESRD DSYLSALSGV LEKHRATAVD LLDGDELSSF LARLNDDINN 190 200 210 220 230 240 LKAMLRAIYI AGHATESFSD FVVGHGELWS AQMLAAVVRK SGLDCTWMDA RDVLVVIPTS 250 260 270 280 290 300 SNQVDPDFVE SEKRLEKWFT QNSAKIIIAT GFIASTPQNI PTTLKRDGSD FSAAIMSALF 310 320 330 340 350 360 RSHQLTIWTD VDGVYSADPR KVSEAVVLKT LSYQEAWEMS YFGANVLHPR TIIPVMKYDI 370 380 390 400 410 420 PIVIRNIFNL SAPGTMICRQ IDDEDGFKLD APVKGFATID NLALVNVEGT GMAGVPGTAS 430 440 450 460 470 480 AIFSAVKEVG ANVIMISQAS SEHSVCFAVP EKEVKAVSEA LNSRFRQALA GGRLSQIEII 490 500 510 520 530 540 PNCSILAAVG QKMASTPGVS ATFFNALAKA NINIRAIAQG CSEFNITVVV KREDCIRALR 550 560 570 580 590 600 AVHSRFYLSR TTLAVGIIGP GLIGGTLLDQ IRDQAAVLKE EFKIDLRVIG ITGSSKMLMS 610 620 630 640 650 660 ESGIDLSRWR ELMKEEGEKA DMEKFTQYVK GNHFIPNSVM VDCTADADIA SCYYDWLLRG 670 680 690 700 710 720 IHVVTPNKKA NSGPLDQYLK IRDLQRKSYT HYFYEATVGA GLPIISTLRG LLETGDKILR 730 740 750 760 770 780 IEGIFSGTLS YLFNNFVGTR SFSEVVAEAK QAGFTEPDPR DDLSGTDVAR KVTILARESG 790 800 810 820 830 840 LKLDLEGLPV QNLVPKPLQA CASAEEFMEK LPQFDEELSK QREEAEAAGE VLRYVGVVDA 850 860 870 880 890 900 VEKKGTVELK RYKKDHPFAQ LSGADNIIAF TTKRYKEQPL IVRGPGAGAQ VTAGGIFSDI 910 LRLAFYLGAP S

References

	« Hide 'large scale' referencesShow 'large scale' references »
[1]	"Sequence and analysis of chromosome 1 of the plant Arabidopsis thaliana." Theologis A., Ecker J.R., Palm C.J., Federspiel N.A., Kaul S., White O., Alonso J., Altafi H., Araujo R., Bowman C.L., Brooks S.Y., Buehler E., Chan A., Chao Q., Chen H., Cheuk R.F., Chin C.W., Chung M.K. , Conn L., Conway A.B., Conway A.R., Creasy T.H., Dewar K., Dunn P., Etgu P., Feldblyum T.V., Feng J.-D., Fong B., Fujii C.Y., Gill J.E., Goldsmith A.D., Haas B., Hansen N.F., Hughes B., Huizar L., Hunter J.L., Jenkins J., Johnson-Hopson C., Khan S., Khaykin E., Kim C.J., Koo H.L., Kremenetskaia I., Kurtz D.B., Kwan A., Lam B., Langin-Hooper S., Lee A., Lee J.M., Lenz C.A., Li J.H., Li Y.-P., Lin X., Liu S.X., Liu Z.A., Luros J.S., Maiti R., Marziali A., Militscher J., Miranda M., Nguyen M., Nierman W.C., Osborne B.I., Pai G., Peterson J., Pham P.K., Rizzo M., Rooney T., Rowley D., Sakano H., Salzberg S.L., Schwartz J.R., Shinn P., Southwick A.M., Sun H., Tallon L.J., Tambunga G., Toriumi M.J., Town C.D., Utterback T., Van Aken S., Vaysberg M., Vysotskaia V.S., Walker M., Wu D., Yu G., Fraser C.M., Venter J.C., Davis R.W. Nature 408:816-820(2000) [PubMed] [Europe PMC] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA]. Strain: cv. Columbia.
[2]	The Arabidopsis Information Resource (TAIR) Submitted (APR-2011) to the EMBL/GenBank/DDBJ databases Cited for: GENOME REANNOTATION. Strain: cv. Columbia.
[3]	"Overproduction, purification, and characterization of recombinant bifunctional threonine-sensitive aspartate kinase-homoserine dehydrogenase from Arabidopsis thaliana." Paris S., Wessel P.M., Dumas R. Protein Expr. Purif. 24:105-110(2002) [PubMed] [Europe PMC] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [MRNA].
[4]	"Functional annotation of a full-length Arabidopsis cDNA collection." Seki M., Narusaka M., Kamiya A., Ishida J., Satou M., Sakurai T., Nakajima M., Enju A., Akiyama K., Oono Y., Muramatsu M., Hayashizaki Y., Kawai J., Carninci P., Itoh M., Ishii Y., Arakawa T., Shibata K., Shinagawa A., Shinozaki K. Science 296:141-145(2002) [PubMed] [Europe PMC] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [LARGE SCALE MRNA]. Strain: cv. Columbia.
[5]	"Molecular analysis of the aspartate kinase-homoserine dehydrogenase gene from Arabidopsis thaliana." Ghislain M., Frankard V., Vandenbossche D., Matthews B., Jacobs M. Plant Mol. Biol. 24:835-851(1994) [PubMed] [Europe PMC] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [GENOMIC DNA] OF 1-573. Strain: cv. Columbia.
[6]	"Identification of six novel allosteric effectors of Arabidopsis thaliana aspartate kinase-homoserine dehydrogenase isoforms. Physiological context sets the specificity." Curien G., Ravanel S., Robert M., Dumas R. J. Biol. Chem. 280:41178-41183(2005) [PubMed] [Europe PMC] [Abstract] Cited for: FUNCTION, ENZYME REGULATION, BIOPHYSICOCHEMICAL PROPERTIES.
+	Additional computationally mapped references.

Cross-references

Sequence databases
EMBL GenBank DDBJ	AC004793 Genomic DNA. Translation: AAD21689.1. AC007654 Genomic DNA. Translation: AAF24602.1. Sequence problems. CP002684 Genomic DNA. Translation: AEE31330.1. AK118779 mRNA. Translation: BAC43372.1. X71364 Genomic DNA. Translation: CAA50500.2. Sequence problems.
IPI	IPI00531888.
PIR	E86438. S46497.
RefSeq	NP_174408.1. NM_102861.3.
UniGene	At.48251. At.71214.
3D structure databases
ProteinModelPortal	Q9SA18.
SMR	Q9SA18. Positions 86-546, 549-904.
ModBase	Search...
Proteomic databases
PaxDb	Q9SA18.
PRIDE	Q9SA18.
Protocols and materials databases
StructuralBiologyKnowledgebase	Search...
Genome annotation databases
EnsemblPlants	AT1G31230.1; AT1G31230.1; AT1G31230.
GeneID	840011.
KEGG	ath:AT1G31230.
Organism-specific databases
TAIR	At1g31230.
Phylogenomic databases
eggNOG	COG0527.
HOGENOM	HOG000271593.
InParanoid	Q9SA18.
KO	K12524.
OMA	DDPLYKV.
PhylomeDB	Q9SA18.
ProtClustDB	CLSN2682367.
Enzyme and pathway databases
SABIO-RK	Q9SA18.
UniPathway	UPA00034; UER00015. UPA00050; UER00063. UPA00050; UER00461. UPA00051; UER00462. UPA00051; UER00465.
Gene expression databases
Genevestigator	Q9SA18.
GermOnline	AT1G31230. Arabidopsis thaliana.
Family and domain databases
Gene3D	3.40.1160.10. 2 hits. 3.40.50.720. 1 hit.
InterPro	IPR002912. ACT_dom. IPR001048. Asp/Glu/Uridylate_kinase. IPR005106. Asp/hSer_DH_NAD-bd. IPR001341. Asp_kinase_dom. IPR018042. Aspartate_kinase_CS. IPR011147. Bifunc_aspartokin/hSer_DH. IPR001342. HDH_cat. IPR019811. HDH_CS. IPR016040. NAD(P)-bd_dom. [Graphical view]
Pfam	PF00696. AA_kinase. 1 hit. PF01842. ACT. 2 hits. PF00742. Homoserine_dh. 1 hit. PF03447. NAD_binding_3. 1 hit. [Graphical view]
PIRSF	PIRSF000727. ThrA. 1 hit.
SUPFAM	SSF53633. Aa_kinase. 1 hit.
TIGRFAMs	TIGR00657. asp_kinases. 1 hit.
PROSITE	PS00324. ASPARTOKINASE. 1 hit. PS01042. HOMOSER_DHGENASE. 1 hit. [Graphical view]
ProtoNet	Search...

Entry information

Entry name

AKH1_ARATH

Accession

Primary (citable) accession number: Q9SA18
Secondary accession number(s): Q8GWK9, Q9SHF9, Q9SW59

Entry history

Integrated into UniProtKB/Swiss-Prot:	July 25, 2006
Last sequence update:	May 1, 2000
Last modified:	May 1, 2013
This is version 96 of the entry and version 1 of the sequence. [Complete history]

Entry status

Reviewed (UniProtKB/Swiss-Prot)

Annotation program

Plant Protein Annotation Program