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Protein

Aspartokinase 2, chloroplastic

Gene

AK2

Organism
Arabidopsis thaliana (Mouse-ear cress)
Status
Reviewed-Annotation score: -Experimental evidence at protein leveli

Functioni

Involved in the first step of essential amino acids lysine, threonine, methionine and isoleucine synthesis via the aspartate-family pathway.

Catalytic activityi

ATP + L-aspartate = ADP + 4-phospho-L-aspartate.

Enzyme regulationi

Allosterically inhibited by lysine, but not by S-adenosyl-L-methionine (SAM). K(0.5) for lysine in the presence of physiological concentrations of substrates is 12.5 µM. No inhibition by threonine or leucine and no activation or inhibition by alanine, cysteine, isoleucine, serine, valine, methionine, glutamine, asparagine, glutamic acid or arginine.1 Publication

Kineticsi

K(cat) is 14.5/sec.
  1. KM=980 µM for ATP1 Publication
  2. KM=1940 µM for aspartate1 Publication

    Pathwayi: L-lysine biosynthesis via DAP pathway

    This protein is involved in step 1 of the subpathway that synthesizes (S)-tetrahydrodipicolinate from L-aspartate.
    Proteins known to be involved in the 4 steps of the subpathway in this organism are:
    1. AK1 (AXX17_At5g12690), Aspartokinase 2, chloroplastic (AK2), Aspartokinase (AXX17_At5g13510), Aspartokinase 1, chloroplastic (AK1), Aspartokinase (CARAB-AK-LYS), Aspartokinase 3, chloroplastic (AK3), Aspartokinase (AXX17_At3g01160), Bifunctional aspartokinase/homoserine dehydrogenase 2, chloroplastic (AKHSDH2), Aspartokinase (AXX17_At3g01160), Aspartokinase (AXX17_At3g01160), Bifunctional aspartokinase/homoserine dehydrogenase 1, chloroplastic (AKHSDH1)
    2. no protein annotated in this organism
    3. 4-hydroxy-tetrahydrodipicolinate synthase 1, chloroplastic (DHDPS1), 4-hydroxy-tetrahydrodipicolinate synthase 2, chloroplastic (DHDPS2)
    4. 4-hydroxy-tetrahydrodipicolinate reductase 2, chloroplastic (DAPB2), 4-hydroxy-tetrahydrodipicolinate reductase 1, chloroplastic (DAPB1)
    This subpathway is part of the pathway L-lysine biosynthesis via DAP pathway, which is itself part of Amino-acid biosynthesis.
    View all proteins of this organism that are known to be involved in the subpathway that synthesizes (S)-tetrahydrodipicolinate from L-aspartate, the pathway L-lysine biosynthesis via DAP pathway and in Amino-acid biosynthesis.

    Pathwayi: L-methionine biosynthesis via de novo pathway

    This protein is involved in step 1 of the subpathway that synthesizes L-homoserine from L-aspartate.
    Proteins known to be involved in the 3 steps of the subpathway in this organism are:
    1. AK1 (AXX17_At5g12690), Aspartokinase 2, chloroplastic (AK2), Aspartokinase (AXX17_At5g13510), Aspartokinase 1, chloroplastic (AK1), Aspartokinase (CARAB-AK-LYS), Aspartokinase 3, chloroplastic (AK3), Aspartokinase (AXX17_At3g01160), Bifunctional aspartokinase/homoserine dehydrogenase 2, chloroplastic (AKHSDH2), Aspartokinase (AXX17_At3g01160), Aspartokinase (AXX17_At3g01160), Bifunctional aspartokinase/homoserine dehydrogenase 1, chloroplastic (AKHSDH1)
    2. no protein annotated in this organism
    3. Homoserine dehydrogenase (AXX17_At5g21030), Homoserine dehydrogenase (At5g21060), Homoserine dehydrogenase (AXX17_At5g21030), Homoserine dehydrogenase (At5g21060), Homoserine dehydrogenase, Homoserine dehydrogenase (At5g21060), Bifunctional aspartokinase/homoserine dehydrogenase 2, chloroplastic (AKHSDH2), Bifunctional aspartokinase/homoserine dehydrogenase 1, chloroplastic (AKHSDH1)
    This subpathway is part of the pathway L-methionine biosynthesis via de novo pathway, which is itself part of Amino-acid biosynthesis.
    View all proteins of this organism that are known to be involved in the subpathway that synthesizes L-homoserine from L-aspartate, the pathway L-methionine biosynthesis via de novo pathway and in Amino-acid biosynthesis.

    Pathwayi: L-threonine biosynthesis

    This protein is involved in step 1 of the subpathway that synthesizes L-threonine from L-aspartate.
    Proteins known to be involved in the 5 steps of the subpathway in this organism are:
    1. AK1 (AXX17_At5g12690), Aspartokinase 2, chloroplastic (AK2), Aspartokinase (AXX17_At5g13510), Aspartokinase 1, chloroplastic (AK1), Aspartokinase (CARAB-AK-LYS), Aspartokinase 3, chloroplastic (AK3), Aspartokinase (AXX17_At3g01160), Bifunctional aspartokinase/homoserine dehydrogenase 2, chloroplastic (AKHSDH2), Aspartokinase (AXX17_At3g01160), Aspartokinase (AXX17_At3g01160), Bifunctional aspartokinase/homoserine dehydrogenase 1, chloroplastic (AKHSDH1)
    2. no protein annotated in this organism
    3. Homoserine dehydrogenase (AXX17_At5g21030), Homoserine dehydrogenase (At5g21060), Homoserine dehydrogenase (AXX17_At5g21030), Homoserine dehydrogenase (At5g21060), Homoserine dehydrogenase, Homoserine dehydrogenase (At5g21060), Bifunctional aspartokinase/homoserine dehydrogenase 2, chloroplastic (AKHSDH2), Bifunctional aspartokinase/homoserine dehydrogenase 1, chloroplastic (AKHSDH1)
    4. Homoserine kinase (HSK)
    5. Threonine synthase 2, chloroplastic (TS2), Threonine synthase 1, chloroplastic (TS1)
    This subpathway is part of the pathway L-threonine biosynthesis, which is itself part of Amino-acid biosynthesis.
    View all proteins of this organism that are known to be involved in the subpathway that synthesizes L-threonine from L-aspartate, the pathway L-threonine biosynthesis and in Amino-acid biosynthesis.

    Sites

    Feature keyPosition(s)DescriptionActionsGraphical viewLength
    Binding sitei87ATPBy similarity1
    Binding sitei90ATP; via amide nitrogenBy similarity1
    Binding sitei119ATPBy similarity1
    Binding sitei203SubstrateBy similarity1

    GO - Molecular functioni

    GO - Biological processi

    Keywordsi

    Molecular functionKinase, Transferase
    Biological processAmino-acid biosynthesis, Threonine biosynthesis
    LigandATP-binding, Nucleotide-binding

    Enzyme and pathway databases

    BioCyciARA:AT5G14060-MONOMER
    BRENDAi2.7.2.4 399
    SABIO-RKiO23653
    UniPathwayiUPA00034; UER00015
    UPA00050; UER00461
    UPA00051; UER00462

    Names & Taxonomyi

    Protein namesi
    Recommended name:
    Aspartokinase 2, chloroplastic (EC:2.7.2.4)
    Alternative name(s):
    Aspartate kinase 2
    Gene namesi
    Name:AK2
    Synonyms:AK-LYS2, CARAB-AK-LYS
    Ordered Locus Names:At5g14060
    ORF Names:MUA22.6
    OrganismiArabidopsis thaliana (Mouse-ear cress)
    Taxonomic identifieri3702 [NCBI]
    Taxonomic lineageiEukaryotaViridiplantaeStreptophytaEmbryophytaTracheophytaSpermatophytaMagnoliophytaeudicotyledonsGunneridaePentapetalaerosidsmalvidsBrassicalesBrassicaceaeCamelineaeArabidopsis
    Proteomesi
    • UP000006548 Componenti: Chromosome 5

    Organism-specific databases

    AraportiAT5G14060
    TAIRilocus:2174708 AT5G14060

    Subcellular locationi

    Extracellular region or secreted Cytosol Plasma membrane Cell wall Cytoskeleton Vacuole Chloroplast Endosome Peroxisome ER Golgi apparatus Nucleus Mitochondrion Manual annotation Automatic computational assertion Graphics by Christian Stolte; Source: COMPARTMENTS

    Keywords - Cellular componenti

    Chloroplast, Plastid

    PTM / Processingi

    Molecule processing

    Feature keyPosition(s)DescriptionActionsGraphical viewLength
    Transit peptidei1 – 84ChloroplastSequence analysisAdd BLAST84
    ChainiPRO_000024815885 – 544Aspartokinase 2, chloroplasticAdd BLAST460

    Proteomic databases

    PaxDbiO23653
    PRIDEiO23653

    PTM databases

    iPTMnetiO23653

    Expressioni

    Tissue specificityi

    Expressed in stems, leaves, floral organs and young seedlings.1 Publication

    Gene expression databases

    ExpressionAtlasiO23653 baseline and differential
    GenevisibleiO23653 AT

    Interactioni

    Protein-protein interaction databases

    STRINGi3702.AT5G14060.1

    Structurei

    3D structure databases

    ProteinModelPortaliO23653
    SMRiO23653
    ModBaseiSearch...
    MobiDBiSearch...

    Family & Domainsi

    Domains and Repeats

    Feature keyPosition(s)DescriptionActionsGraphical viewLength
    Domaini401 – 479ACT 1PROSITE-ProRule annotationAdd BLAST79
    Domaini481 – 544ACT 2PROSITE-ProRule annotationAdd BLAST64

    Sequence similaritiesi

    Belongs to the aspartokinase family.Curated

    Keywords - Domaini

    Repeat, Transit peptide

    Phylogenomic databases

    eggNOGiKOG0456 Eukaryota
    COG0527 LUCA
    HOGENOMiHOG000293094
    InParanoidiO23653
    KOiK00928
    OMAiINIMMIS
    OrthoDBiEOG0936086O
    PhylomeDBiO23653

    Family and domain databases

    Gene3Di3.40.1160.10, 2 hits
    InterProiView protein in InterPro
    IPR036393 AceGlu_kinase-like_sf
    IPR002912 ACT_dom
    IPR001048 Asp/Glu/Uridylate_kinase
    IPR001341 Asp_kinase
    IPR018042 Aspartate_kinase_CS
    PfamiView protein in Pfam
    PF00696 AA_kinase, 1 hit
    SUPFAMiSSF53633 SSF53633, 1 hit
    TIGRFAMsiTIGR00657 asp_kinases, 1 hit
    PROSITEiView protein in PROSITE
    PS51671 ACT, 2 hits
    PS00324 ASPARTOKINASE, 1 hit

    Sequencei

    Sequence statusi: Complete.

    Sequence processingi: The displayed sequence is further processed into a mature form.

    O23653-1 [UniParc]FASTAAdd to basket

    « Hide

            10         20         30         40         50
    MASLQLYGVK TPGLALSSKR LEFASKGACF SVTLPSSSAV FRDVEHSCRN
    60 70 80 90 100
    IGLRVSCEAL RVDLLQRKEP ETCDSSGTGK ELTCVMKFGG SSVESAERMK
    110 120 130 140 150
    EVANLILSFP DERPVIVLSA MGKTTNKLLK AGEKAVTCGV TNVESIEELS
    160 170 180 190 200
    FIKELHLRTA HELGVETTVI EKHLEGLHQL LKGISMMKEL TLRTRDYLVS
    210 220 230 240 250
    FGECMSTRLF SAYLNKIGHK ARQYDAFEIG FITTDDFTNA DILEATYPAV
    260 270 280 290 300
    SKTLVGDWSK ENAVPVVTGY LGKGWRSCAI TTLGRGGSDL TATTIGKALG
    310 320 330 340 350
    LREIQVWKDV DGVLTCDPNI YPGAQSVPYL TFDEAAELAY FGAQVLHPLS
    360 370 380 390 400
    MRPARDGDIP VRVKNSYNPT APGTVITRSR DMSKAVLTSI VLKRNVTMLD
    410 420 430 440 450
    IASTRMLGQY GFLAKVFTTF EDLGISVDVV ATSEVSISLT LDPAKLWGRE
    460 470 480 490 500
    LIQRVNELDN LVEELEKIAV VKLLQRRSII SLIGNVQKSS LILEKVFQVF
    510 520 530 540
    RSNGVNVQMI SQGASKVNIS LIVNDEEAEQ CVRALHSAFF ETDP
    Length:544
    Mass (Da):59,605
    Last modified:September 5, 2006 - v2
    Checksum:i7DBCFDC1138645AC
    GO

    Experimental Info

    Feature keyPosition(s)DescriptionActionsGraphical viewLength
    Sequence conflicti94E → G in AAB63104 (PubMed:9207844).Curated1
    Sequence conflicti94E → G in CAC06395 (Ref. 2) Curated1
    Sequence conflicti107L → F in AAB63104 (PubMed:9207844).Curated1
    Sequence conflicti107L → F in CAC06395 (Ref. 2) Curated1
    Sequence conflicti125T → I in AAB63104 (PubMed:9207844).Curated1
    Sequence conflicti125T → I in CAC06395 (Ref. 2) Curated1
    Sequence conflicti144E → G in AAB63104 (PubMed:9207844).Curated1

    Sequence databases

    Select the link destinations:
    EMBLi
    GenBanki
    DDBJi
    Links Updated
    U62020 mRNA Translation: AAB63104.1
    Y16255 Genomic DNA Translation: CAC06395.1
    AB007650 Genomic DNA Translation: BAB08285.1
    CP002688 Genomic DNA Translation: AED91982.1
    CP002688 Genomic DNA Translation: AED91983.1
    RefSeqiNP_001078581.1, NM_001085112.2
    NP_196910.1, NM_121409.4
    UniGeneiAt.21761

    Genome annotation databases

    EnsemblPlantsiAT5G14060.1; AT5G14060.1; AT5G14060
    AT5G14060.2; AT5G14060.2; AT5G14060
    GeneIDi831255
    GrameneiAT5G14060.1; AT5G14060.1; AT5G14060
    AT5G14060.2; AT5G14060.2; AT5G14060
    KEGGiath:AT5G14060

    Similar proteinsi

    Entry informationi

    Entry nameiAK2_ARATH
    AccessioniPrimary (citable) accession number: O23653
    Secondary accession number(s): Q9FMU4, Q9FY44
    Entry historyiIntegrated into UniProtKB/Swiss-Prot: September 5, 2006
    Last sequence update: September 5, 2006
    Last modified: April 25, 2018
    This is version 120 of the entry and version 2 of the sequence. See complete history.
    Entry statusiReviewed (UniProtKB/Swiss-Prot)
    Annotation programPlant Protein Annotation Program

    Miscellaneousi

    Keywords - Technical termi

    Complete proteome, Reference proteome
    UniProt is an ELIXIR core data resource
    Main funding by: National Institutes of Health