ID   KHSE_MICDP              Reviewed;         307 AA.
AC   P04947;
DT   13-AUG-1987, integrated into UniProtKB/Swiss-Prot.
DT   13-AUG-1987, sequence version 1.
DT   03-AUG-2022, entry version 105.
DE   RecName: Full=Homoserine kinase;
DE            Short=HK;
DE            Short=HSK;
DE            EC=2.7.1.39;
GN   Name=thrB;
OS   Microchaete diplosiphon (Fremyella diplosiphon).
OC   Bacteria; Cyanobacteria; Nostocales; Rivulariaceae; Microchaete.
OX   NCBI_TaxID=1197;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [GENOMIC DNA].
RX   PubMed=2838727; DOI=10.1111/j.1365-2958.1987.tb00525.x;
RA   Parsot C., Mazel D.;
RT   "Cloning and nucleotide sequence of the thrB gene from the cyanobacterium
RT   Calothrix PCC 7601.";
RL   Mol. Microbiol. 1:45-52(1987).
CC   -!- FUNCTION: Catalyzes the ATP-dependent phosphorylation of L-homoserine
CC       to L-homoserine phosphate. {ECO:0000250}.
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;
CC   -!- PATHWAY: Amino-acid biosynthesis; L-threonine biosynthesis; L-threonine
CC       from L-aspartate: step 4/5.
CC   -!- SUBCELLULAR LOCATION: Cytoplasm {ECO:0000305}.
CC   -!- SIMILARITY: Belongs to the GHMP kinase family. Homoserine kinase
CC       subfamily. {ECO:0000305}.
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DR   EMBL; Y00522; CAA68576.1; -; Genomic_DNA.
DR   AlphaFoldDB; P04947; -.
DR   SMR; P04947; -.
DR   UniPathway; UPA00050; UER00064.
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..307
FT                   /note="Homoserine kinase"
FT                   /id="PRO_0000156572"
FT   BINDING         92..102
FT                   /ligand="ATP"
FT                   /ligand_id="ChEBI:CHEBI:30616"
FT                   /evidence="ECO:0000255"
SQ   SEQUENCE   307 AA;  31991 MW;  C4D97B891AC20B08 CRC64;
     MSVVSSVTVT VPATTANLGP GFDCIGAALT LYNKVKFTRL DAGGLIIHVT GKEAEGVNTD
     ESNLLYQAFV KLYQHIEQIP PSVKIEIDLG VPLARGLGSS ATAIVGGLVA ANQLAGEPLS
     QLQVMELAIA MEGHPDNVVP ALLGGCRLAA TSAEGWEICD VPWDENVVPV VAIPDFELST
     QEARRVLPTE FSRADAIFNT AHLGLLLRGL ATGKGEWLKT ALQDKLHQPY RKALIPGYDA
     VNQAAVAAGA YGMVISGAGP TLLALADAQN SQAVAAAMQT AWQTVGITAD VRSLSLDNQG
     ASSLNEG