ID   KHSE_BUCAP              Reviewed;         309 AA.
AC   Q8K9V0;
DT   08-NOV-2002, integrated into UniProtKB/Swiss-Prot.
DT   01-OCT-2002, sequence version 1.
DT   03-AUG-2022, entry version 116.
DE   RecName: Full=Homoserine kinase {ECO:0000255|HAMAP-Rule:MF_00384};
DE            Short=HK {ECO:0000255|HAMAP-Rule:MF_00384};
DE            Short=HSK {ECO:0000255|HAMAP-Rule:MF_00384};
DE            EC=2.7.1.39 {ECO:0000255|HAMAP-Rule:MF_00384};
GN   Name=thrB {ECO:0000255|HAMAP-Rule:MF_00384}; OrderedLocusNames=BUsg_187;
OS   Buchnera aphidicola subsp. Schizaphis graminum (strain Sg).
OC   Bacteria; Proteobacteria; Gammaproteobacteria; Enterobacterales;
OC   Erwiniaceae; Buchnera.
OX   NCBI_TaxID=198804;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC   STRAIN=Sg;
RX   PubMed=12089438; DOI=10.1126/science.1071278;
RA   Tamas I., Klasson L., Canbaeck B., Naeslund A.K., Eriksson A.-S.,
RA   Wernegreen J.J., Sandstroem J.P., Moran N.A., Andersson S.G.E.;
RT   "50 million years of genomic stasis in endosymbiotic bacteria.";
RL   Science 296:2376-2379(2002).
CC   -!- FUNCTION: Catalyzes the ATP-dependent phosphorylation of L-homoserine
CC       to L-homoserine phosphate. {ECO:0000255|HAMAP-Rule:MF_00384}.
CC   -!- CATALYTIC ACTIVITY:
CC       Reaction=ATP + L-homoserine = ADP + H(+) + O-phospho-L-homoserine;
CC         Xref=Rhea:RHEA:13985, ChEBI:CHEBI:15378, ChEBI:CHEBI:30616,
CC         ChEBI:CHEBI:57476, ChEBI:CHEBI:57590, ChEBI:CHEBI:456216;
CC         EC=2.7.1.39; Evidence={ECO:0000255|HAMAP-Rule:MF_00384};
CC   -!- PATHWAY: Amino-acid biosynthesis; L-threonine biosynthesis; L-threonine
CC       from L-aspartate: step 4/5. {ECO:0000255|HAMAP-Rule:MF_00384}.
CC   -!- SUBCELLULAR LOCATION: Cytoplasm {ECO:0000255|HAMAP-Rule:MF_00384}.
CC   -!- SIMILARITY: Belongs to the GHMP kinase family. Homoserine kinase
CC       subfamily. {ECO:0000255|HAMAP-Rule:MF_00384}.
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DR   EMBL; AE013218; AAM67752.1; -; Genomic_DNA.
DR   RefSeq; WP_011053719.1; NC_004061.1.
DR   AlphaFoldDB; Q8K9V0; -.
DR   SMR; Q8K9V0; -.
DR   STRING; 198804.BUsg_187; -.
DR   EnsemblBacteria; AAM67752; AAM67752; BUsg_187.
DR   KEGG; bas:BUsg_187; -.
DR   eggNOG; COG0083; Bacteria.
DR   HOGENOM; CLU_041243_1_1_6; -.
DR   OMA; CANRIPH; -.
DR   OrthoDB; 610857at2; -.
DR   UniPathway; UPA00050; UER00064.
DR   Proteomes; UP000000416; Chromosome.
DR   GO; GO:0005737; C:cytoplasm; IEA:UniProtKB-SubCell.
DR   GO; GO:0005524; F:ATP binding; IEA:UniProtKB-UniRule.
DR   GO; GO:0004413; F:homoserine kinase activity; IEA:UniProtKB-UniRule.
DR   GO; GO:0016310; P:phosphorylation; IEA:UniProtKB-KW.
DR   GO; GO:0009088; P:threonine biosynthetic process; IEA:UniProtKB-UniRule.
DR   Gene3D; 3.30.230.10; -; 1.
DR   Gene3D; 3.30.70.890; -; 1.
DR   HAMAP; MF_00384; Homoser_kinase; 1.
DR   InterPro; IPR013750; GHMP_kinase_C_dom.
DR   InterPro; IPR036554; GHMP_kinase_C_sf.
DR   InterPro; IPR006204; GHMP_kinase_N_dom.
DR   InterPro; IPR006203; GHMP_knse_ATP-bd_CS.
DR   InterPro; IPR000870; Homoserine_kinase.
DR   InterPro; IPR020568; Ribosomal_S5_D2-typ_fold.
DR   InterPro; IPR014721; Ribosomal_S5_D2-typ_fold_subgr.
DR   Pfam; PF08544; GHMP_kinases_C; 1.
DR   Pfam; PF00288; GHMP_kinases_N; 1.
DR   PIRSF; PIRSF000676; Homoser_kin; 1.
DR   SUPFAM; SSF54211; SSF54211; 1.
DR   SUPFAM; SSF55060; SSF55060; 1.
DR   TIGRFAMs; TIGR00191; thrB; 1.
DR   PROSITE; PS00627; GHMP_KINASES_ATP; 1.
PE   3: Inferred from homology;
KW   Amino-acid biosynthesis; ATP-binding; Cytoplasm; Kinase;
KW   Nucleotide-binding; Threonine biosynthesis; Transferase.
FT   CHAIN           1..309
FT                   /note="Homoserine kinase"
FT                   /id="PRO_0000156556"
FT   BINDING         91..101
FT                   /ligand="ATP"
FT                   /ligand_id="ChEBI:CHEBI:30616"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00384"
SQ   SEQUENCE   309 AA;  34036 MW;  76118A4C8CD1C3D3 CRC64;
     MIKIYAPASV ANVGVGFDIL GAAIIPINGT LLGDCVTVKL SKKFELINKG IFSNKLPINK
     EQNIVWKCWF KFCKVIKKNI PVSIILEKNM PIGSGLGSSA CSVVATLVAI NQICNNPLNS
     KELLLLMGEI EGEISGSIHY DNVAPSYLGG LQLILEDSDI ISQKIPNFKH WFWIIAWPGI
     KVSTAEARKI LPKEYKKDIC IKNSRYLAGF IHASYTKQSH LAARCMQDFI AEPYRSKLLP
     NFLNAKEKIK KIGAISCGIS GSGPTIFAIS DKIKTAEKIS LWLKNNYLQN KTGFVHICAV
     DVKGVRKIG