ID   GLN1A_STAAR             Reviewed;         446 AA.
AC   Q6GHC6;
DT   15-FEB-2005, integrated into UniProtKB/Swiss-Prot.
DT   19-JUL-2004, sequence version 1.
DT   27-MAR-2024, entry version 101.
DE   RecName: Full=Glutamine synthetase {ECO:0000250|UniProtKB:P12425};
DE            Short=GS {ECO:0000250|UniProtKB:P12425};
DE            EC=6.3.1.2 {ECO:0000250|UniProtKB:P12425};
DE   AltName: Full=Glutamate--ammonia ligase {ECO:0000250|UniProtKB:P12425};
DE   AltName: Full=Glutamine synthetase I alpha {ECO:0000250|UniProtKB:P12425};
DE            Short=GSI alpha {ECO:0000250|UniProtKB:P12425};
GN   Name=glnA {ECO:0000250|UniProtKB:P12425}; OrderedLocusNames=SAR1284;
OS   Staphylococcus aureus (strain MRSA252).
OC   Bacteria; Bacillota; Bacilli; Bacillales; Staphylococcaceae;
OC   Staphylococcus.
OX   NCBI_TaxID=282458;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC   STRAIN=MRSA252;
RX   PubMed=15213324; DOI=10.1073/pnas.0402521101;
RA   Holden M.T.G., Feil E.J., Lindsay J.A., Peacock S.J., Day N.P.J.,
RA   Enright M.C., Foster T.J., Moore C.E., Hurst L., Atkin R., Barron A.,
RA   Bason N., Bentley S.D., Chillingworth C., Chillingworth T., Churcher C.,
RA   Clark L., Corton C., Cronin A., Doggett J., Dowd L., Feltwell T., Hance Z.,
RA   Harris B., Hauser H., Holroyd S., Jagels K., James K.D., Lennard N.,
RA   Line A., Mayes R., Moule S., Mungall K., Ormond D., Quail M.A.,
RA   Rabbinowitsch E., Rutherford K.M., Sanders M., Sharp S., Simmonds M.,
RA   Stevens K., Whitehead S., Barrell B.G., Spratt B.G., Parkhill J.;
RT   "Complete genomes of two clinical Staphylococcus aureus strains: evidence
RT   for the rapid evolution of virulence and drug resistance.";
RL   Proc. Natl. Acad. Sci. U.S.A. 101:9786-9791(2004).
CC   -!- FUNCTION: Glutamine synthetase (GS) is an unusual multitasking protein
CC       that functions as an enzyme, a transcription coregulator, and a
CC       chaperone in ammonium assimilation and in the regulation of genes
CC       involved in nitrogen metabolism. It catalyzes the ATP-dependent
CC       biosynthesis of glutamine from glutamate and ammonia. Feedback-
CC       inhibited GlnA also interacts with and regulates the activity of the
CC       transcriptional regulator TnrA. During nitrogen limitation, TnrA is in
CC       its DNA-binding active state and turns on the transcription of genes
CC       required for nitrogen assimilation. Under conditions of nitrogen
CC       excess, feedback-inhibited GlnA forms a stable complex with TnrA, which
CC       inhibits its DNA-binding activity. In contrast, feedback-inhibited GlnA
CC       acts as a chaperone to stabilize the DNA-binding activity of GlnR,
CC       which represses the transcription of nitrogen assimilation genes.
CC       {ECO:0000250|UniProtKB:P12425}.
CC   -!- CATALYTIC ACTIVITY:
CC       Reaction=ATP + L-glutamate + NH4(+) = ADP + H(+) + L-glutamine +
CC         phosphate; Xref=Rhea:RHEA:16169, ChEBI:CHEBI:15378,
CC         ChEBI:CHEBI:28938, ChEBI:CHEBI:29985, ChEBI:CHEBI:30616,
CC         ChEBI:CHEBI:43474, ChEBI:CHEBI:58359, ChEBI:CHEBI:456216; EC=6.3.1.2;
CC         Evidence={ECO:0000250|UniProtKB:P12425};
CC   -!- COFACTOR:
CC       Name=Mg(2+); Xref=ChEBI:CHEBI:18420;
CC         Evidence={ECO:0000250|UniProtKB:P12425};
CC       Note=Binds 2 Mg(2+) ions per subunit. {ECO:0000250|UniProtKB:P12425};
CC   -!- ACTIVITY REGULATION: Inhibited by glutamine.
CC       {ECO:0000250|UniProtKB:P12425}.
CC   -!- SUBUNIT: Oligomer of 12 subunits arranged in the form of two hexagons.
CC       In its feedback-inhibited form, interacts with TnrA in order to block
CC       its DNA-binding activity. {ECO:0000250|UniProtKB:P12425}.
CC   -!- SUBCELLULAR LOCATION: Cytoplasm {ECO:0000250|UniProtKB:P12425}.
CC   -!- SIMILARITY: Belongs to the glutamine synthetase family. {ECO:0000305}.
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DR   EMBL; BX571856; CAG40287.1; -; Genomic_DNA.
DR   RefSeq; WP_001126604.1; NC_002952.2.
DR   AlphaFoldDB; Q6GHC6; -.
DR   SMR; Q6GHC6; -.
DR   KEGG; sar:SAR1284; -.
DR   HOGENOM; CLU_017290_1_3_9; -.
DR   Proteomes; UP000000596; Chromosome.
DR   GO; GO:0005737; C:cytoplasm; IEA:UniProtKB-SubCell.
DR   GO; GO:0005524; F:ATP binding; IEA:UniProtKB-KW.
DR   GO; GO:0004356; F:glutamine synthetase activity; IEA:UniProtKB-EC.
DR   GO; GO:0046872; F:metal ion binding; IEA:UniProtKB-KW.
DR   GO; GO:0006542; P:glutamine biosynthetic process; IEA:InterPro.
DR   Gene3D; 3.10.20.70; Glutamine synthetase, N-terminal domain; 1.
DR   Gene3D; 3.30.590.10; Glutamine synthetase/guanido kinase, catalytic domain; 1.
DR   InterPro; IPR008147; Gln_synt_N.
DR   InterPro; IPR036651; Gln_synt_N_sf.
DR   InterPro; IPR014746; Gln_synth/guanido_kin_cat_dom.
DR   InterPro; IPR008146; Gln_synth_cat_dom.
DR   InterPro; IPR027303; Gln_synth_gly_rich_site.
DR   InterPro; IPR004809; Gln_synth_I.
DR   InterPro; IPR027302; Gln_synth_N_conserv_site.
DR   NCBIfam; TIGR00653; GlnA; 1.
DR   PANTHER; PTHR43785; GAMMA-GLUTAMYLPUTRESCINE SYNTHETASE; 1.
DR   PANTHER; PTHR43785:SF12; GAMMA-GLUTAMYLPUTRESCINE SYNTHETASE PUUA; 1.
DR   Pfam; PF00120; Gln-synt_C; 1.
DR   Pfam; PF03951; Gln-synt_N; 1.
DR   SMART; SM01230; Gln-synt_C; 1.
DR   SUPFAM; SSF54368; Glutamine synthetase, N-terminal domain; 1.
DR   SUPFAM; SSF55931; Glutamine synthetase/guanido kinase; 1.
DR   PROSITE; PS00180; GLNA_1; 1.
DR   PROSITE; PS00181; GLNA_ATP; 1.
DR   PROSITE; PS51986; GS_BETA_GRASP; 1.
DR   PROSITE; PS51987; GS_CATALYTIC; 1.
PE   3: Inferred from homology;
KW   ATP-binding; Cytoplasm; Ligase; Magnesium; Metal-binding;
KW   Nucleotide-binding.
FT   CHAIN           1..446
FT                   /note="Glutamine synthetase"
FT                   /id="PRO_0000153260"
FT   DOMAIN          18..103
FT                   /note="GS beta-grasp"
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU01330"
FT   DOMAIN          110..446
FT                   /note="GS catalytic"
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU01331"
FT   BINDING         134
FT                   /ligand="Mg(2+)"
FT                   /ligand_id="ChEBI:CHEBI:18420"
FT                   /ligand_label="1"
FT                   /evidence="ECO:0000250|UniProtKB:P12425"
FT   BINDING         136
FT                   /ligand="Mg(2+)"
FT                   /ligand_id="ChEBI:CHEBI:18420"
FT                   /ligand_label="2"
FT                   /evidence="ECO:0000250|UniProtKB:P12425"
FT   BINDING         186
FT                   /ligand="ATP"
FT                   /ligand_id="ChEBI:CHEBI:30616"
FT                   /evidence="ECO:0000250|UniProtKB:P9WN39"
FT   BINDING         191
FT                   /ligand="Mg(2+)"
FT                   /ligand_id="ChEBI:CHEBI:18420"
FT                   /ligand_label="2"
FT                   /evidence="ECO:0000250|UniProtKB:P12425"
FT   BINDING         198
FT                   /ligand="Mg(2+)"
FT                   /ligand_id="ChEBI:CHEBI:18420"
FT                   /ligand_label="2"
FT                   /evidence="ECO:0000250|UniProtKB:P12425"
FT   BINDING         242..243
FT                   /ligand="L-glutamate"
FT                   /ligand_id="ChEBI:CHEBI:29985"
FT                   /evidence="ECO:0000250|UniProtKB:P9WN39"
FT   BINDING         243
FT                   /ligand="L-glutamate"
FT                   /ligand_id="ChEBI:CHEBI:29985"
FT                   /evidence="ECO:0000250|UniProtKB:P12425"
FT   BINDING         247
FT                   /ligand="Mg(2+)"
FT                   /ligand_id="ChEBI:CHEBI:18420"
FT                   /ligand_label="1"
FT                   /evidence="ECO:0000250|UniProtKB:P12425"
FT   BINDING         251
FT                   /ligand="ATP"
FT                   /ligand_id="ChEBI:CHEBI:30616"
FT                   /evidence="ECO:0000250|UniProtKB:P77961"
FT   BINDING         300
FT                   /ligand="L-glutamate"
FT                   /ligand_id="ChEBI:CHEBI:29985"
FT                   /evidence="ECO:0000250|UniProtKB:P0A1P6"
FT   BINDING         306
FT                   /ligand="L-glutamate"
FT                   /ligand_id="ChEBI:CHEBI:29985"
FT                   /evidence="ECO:0000250|UniProtKB:P0A1P6"
FT   BINDING         318
FT                   /ligand="ATP"
FT                   /ligand_id="ChEBI:CHEBI:30616"
FT                   /evidence="ECO:0000250|UniProtKB:P9WN39"
FT   BINDING         318
FT                   /ligand="L-glutamate"
FT                   /ligand_id="ChEBI:CHEBI:29985"
FT                   /evidence="ECO:0000250|UniProtKB:P9WN39"
FT   BINDING         323
FT                   /ligand="ATP"
FT                   /ligand_id="ChEBI:CHEBI:30616"
FT                   /evidence="ECO:0000250|UniProtKB:P9WN39"
FT   BINDING         335
FT                   /ligand="Mg(2+)"
FT                   /ligand_id="ChEBI:CHEBI:18420"
FT                   /ligand_label="1"
FT                   /evidence="ECO:0000250|UniProtKB:P12425"
FT   BINDING         337
FT                   /ligand="L-glutamate"
FT                   /ligand_id="ChEBI:CHEBI:29985"
FT                   /evidence="ECO:0000250|UniProtKB:P0A1P6"
FT   SITE            64
FT                   /note="Important for inhibition by glutamine"
FT                   /evidence="ECO:0000250|UniProtKB:P12425"
SQ   SEQUENCE   446 AA;  50857 MW;  988F5EF566C4C6D4 CRC64;
     MPKRTFTKDD IRKFAEEENV RYLRLQFTDI LGTIKNVEVP VSQLEKVLDN EMMFDGSSIE
     GFVRIEESDM YLHPDLDTWV IFPWTAGQGK VARLICDVYK TDGTPFEGDP RANLKRVLKE
     MEDLGFTDFN LGPEPEFFLF KLDEKGEPTL ELNDDGGYFD LAPTDLGENC RRDIVLELED
     MGFDIEASHH EVAPGQHEID FKYADAVTAC DNIQTFKLVV KTIARKHNLH ATFMPKPLFG
     VNGSGMHFNV SLFKGKENAF FDPNTEMGLT ETAYQFTAGV LKNARGFTAV CNPLVNSYKR
     LVPGYEAPCY IAWSGKNRSP LIRVPSSRGL STRIEVRSVD PAANPYMALA AILESGLDGI
     KNKLKVPEPV NQNIYEMNRE EREAVGIQDL PSTLYTALKA MRENEVIKKA LGNHIYNQFI
     NSKSIEWDYY RTQVSEWERD QYMKQY
//