Reviewed, UniProtKB/Swiss-Prot Q9SA18 (AKH1_ARATH)

Names and origin

Protein names

Recommended name:
    Bifunctional aspartokinase/homoserine dehydrogenase 1, chloroplastic
      Short name=AK-HSDH 1
      Short name=AK-HD 1
Alternative name(s):
    Beta-aspartyl phosphate homoserine 1
Including the following 2 domains:
    1- Recommended name:
            Aspartokinase
              EC=2.7.2.4
    2- Recommended name:
            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) [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	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.5
Pathway	Amino-acid biosynthesis; L-lysine biosynthesis via DAP pathway; 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) 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
Gene Ontology (GO)
Biological process	methionine biosynthetic process Inferred from electronic annotation. Source: UniProtKB-KW oxidation reduction Inferred from electronic annotation. Source: UniProtKB-KW
Cellular component	chloroplast stroma Inferred from direct assay. Source: TAIR
Molecular function	ATP binding Inferred from electronic annotation. Source: UniProtKB-KW NADP or NADPH binding Inferred from electronic annotation. Source: InterPro amino acid binding Inferred from electronic annotation. Source: InterPro aspartate kinase activity Ref.5 Inferred from direct assay. Source: TAIR homoserine dehydrogenase activity Ref.5 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 – 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.3
	Sequence conflict	900	1	I → F in BAC43372. Ref.3

Sequences

	Sequence		Length	Mass (Da)
	Q9SA18-1 [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: 11130712] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA]. Strain: cv. Columbia.
[2]	"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: 11812230] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [MRNA].
[3]	"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: 11910074] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [LARGE SCALE MRNA]. Strain: cv. Columbia.
[4]	"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: 8204822] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [GENOMIC DNA] OF 1-573. Strain: cv. Columbia.
[5]	"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: 16216875] [Abstract] Cited for: FUNCTION, ENZYME REGULATION, BIOPHYSICOCHEMICAL PROPERTIES.

Cross-references

Sequence databases
EMBLGenBankDDBJ	AC004793 Genomic DNA. Translation: AAD21689.1. AC007654 Genomic DNA. Translation: AAF24602.1. Sequence problems. AK118779 mRNA. Translation: BAC43372.1. X71364 Genomic DNA. Translation: CAA50500.2. Sequence problems.
IPI	IPI00531888.
PIR	E86438. S46497.
RefSeq	NP_174408.1.
UniGene	At.71214
3D structure databases
HSSP	HSSP built from PDB template 1EBF based on UniProtKB P31116.
ModBase	Search...
Proteomic databases
PRIDE	Q9SA18.
ProMEX	Q9SA18.
Genome annotation databases
GeneID	840011.
GenomeReviews	Gene locus AT1G31230 in contig CT485782_GR.
KEGG	ath:AT1G31230.
NMPDR	fig|3702.1.peg.3465.
Organism-specific databases
TAIR	At1g31230.
Phylogenomic databases
OMA	Q9SA18. RYLARID.
Enzyme and pathway databases
BRENDA	1.1.1.3. 302. 2.7.2.4. 302.
Gene expression databases
GermOnline	AT1G31230. Arabidopsis thaliana.
Family and domain databases
InterPro	IPR002912. ACT_bd. IPR001048. Asp/Glu/Uridylate_kinase. IPR005106. Asp/hSer_DH_NAD-bd. IPR001341. Asp_kin_reg. IPR018042. Aspartate_kinase_CS. IPR011147. bifunc_aspartokin/hSer_DH. IPR001342. Homoserine_dehydrogenase_cat. IPR019811. Homoserine_dehydrogenase_CS. IPR016040. NAD(P)-bd_dom. [Graphical view]
Gene3D	G3DSA:3.40.1160.10. Aa_kinase. 1 hit. G3DSA:3.40.50.720. NAD(P)-bd. 1 hit.
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.
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:	June 16, 2009
This is version 61 of the entry and version 1 of the sequence. [Complete history]

Entry status

Reviewed (UniProtKB/Swiss-Prot)

Annotation project

PPAP (Plant Proteome Annotation Project)