ID   KHSE_BLOFL              Reviewed;         311 AA.
AC   Q7VQL6;
DT   15-FEB-2005, integrated into UniProtKB/Swiss-Prot.
DT   01-OCT-2003, sequence version 1.
DT   10-JUN-2026, entry version 114.
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=Bfl112;
OS   Blochmanniella floridana.
OC   Bacteria; Pseudomonadati; Pseudomonadota; Gammaproteobacteria;
OC   Enterobacterales; Enterobacteriaceae; ant endosymbionts;
OC   Candidatus Blochmanniella.
OX   NCBI_TaxID=203907;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RX   PubMed=12886019; DOI=10.1073/pnas.1533499100;
RA   Gil R., Silva F.J., Zientz E., Delmotte F., Gonzalez-Candelas F.,
RA   Latorre A., Rausell C., Kamerbeek J., Gadau J., Hoelldobler B.,
RA   van Ham R.C.H.J., Gross R., Moya A.;
RT   "The genome sequence of Blochmannia floridanus: comparative analysis of
RT   reduced genomes.";
RL   Proc. Natl. Acad. Sci. U.S.A. 100:9388-9393(2003).
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=L-homoserine + ATP = O-phospho-L-homoserine + ADP + H(+);
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; BX248583; CAD83633.1; -; Genomic_DNA.
DR   AlphaFoldDB; Q7VQL6; -.
DR   SMR; Q7VQL6; -.
DR   STRING; 203907.Bfl112; -.
DR   KEGG; bfl:Bfl112; -.
DR   eggNOG; COG0083; Bacteria.
DR   HOGENOM; CLU_041243_1_1_6; -.
DR   OrthoDB; 9769912at2; -.
DR   UniPathway; UPA00050; UER00064.
DR   Proteomes; UP000002192; 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:0009088; P:L-threonine biosynthetic process; IEA:UniProtKB-UniRule.
DR   Gene3D; 3.30.230.10; -; 1.
DR   Gene3D; 3.30.70.890; GHMP kinase, C-terminal domain; 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; IPR000870; Homoserine_kinase.
DR   InterPro; IPR020568; Ribosomal_Su5_D2-typ_SF.
DR   InterPro; IPR014721; Ribsml_uS5_D2-typ_fold_subgr.
DR   NCBIfam; NF002288; PRK01212.1-4; 1.
DR   NCBIfam; TIGR00191; thrB; 1.
DR   PANTHER; PTHR20861:SF1; HOMOSERINE KINASE; 1.
DR   PANTHER; PTHR20861; HOMOSERINE/4-DIPHOSPHOCYTIDYL-2-C-METHYL-D-ERYTHRITOL KINASE; 1.
DR   Pfam; PF08544; GHMP_kinases_C; 1.
DR   Pfam; PF00288; GHMP_kinases_N; 1.
DR   PIRSF; PIRSF000676; Homoser_kin; 1.
DR   PRINTS; PR00958; HOMSERKINASE.
DR   SUPFAM; SSF55060; GHMP Kinase, C-terminal domain; 1.
DR   SUPFAM; SSF54211; Ribosomal protein S5 domain 2-like; 1.
PE   3: Inferred from homology;
KW   Amino-acid biosynthesis; ATP-binding; Cytoplasm; Kinase;
KW   Nucleotide-binding; Reference proteome; Threonine biosynthesis;
KW   Transferase.
FT   CHAIN           1..311
FT                   /note="Homoserine kinase"
FT                   /id="PRO_0000156559"
FT   BINDING         91..101
FT                   /ligand="ATP"
FT                   /ligand_id="ChEBI:CHEBI:30616"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00384"
SQ   SEQUENCE   311 AA;  34293 MW;  A46F831FB6483DAC CRC64;
     MIRVYAPASI ANIGVGFDTL GMSISPVNGD KLGDFVSIKD ADNFSIKISG LFYDQIPIKL
     EQNIVFKCWK RFCEISNQIR PVEIKLEKNV PVESGLGSSA CSIVASLVAI NNYYGNLLNN
     DQLLQLMGEM EGKVSGSIHF DNVAPCFLGG MRIFLSKYKN TSQLIPSFDN WIWIIAYPGI
     KVSTVKSRSV LPKQYSLQDC VDYGQYLSGF IHACHTRQEL LAIQCIEDII AEPYRAKLLP
     VDLSFLRSCV KEKGAVSCGI SGSGPTIFVL CNVKNVVDDI SNWLSRFYLQ NSSGFVKVCS
     LNKLGSDIVL G
//