ID   GLN1A_LACLA             Reviewed;         446 AA.
AC   Q9CDL9;
DT   02-NOV-2001, integrated into UniProtKB/Swiss-Prot.
DT   01-JUN-2001, sequence version 1.
DT   27-MAR-2024, entry version 122.
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=LL2200;
GN   ORFNames=L0118;
OS   Lactococcus lactis subsp. lactis (strain IL1403) (Streptococcus lactis).
OC   Bacteria; Bacillota; Bacilli; Lactobacillales; Streptococcaceae;
OC   Lactococcus.
OX   NCBI_TaxID=272623;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC   STRAIN=IL1403;
RX   PubMed=11337471; DOI=10.1101/gr.gr-1697r;
RA   Bolotin A., Wincker P., Mauger S., Jaillon O., Malarme K., Weissenbach J.,
RA   Ehrlich S.D., Sorokin A.;
RT   "The complete genome sequence of the lactic acid bacterium Lactococcus
RT   lactis ssp. lactis IL1403.";
RL   Genome Res. 11:731-753(2001).
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; AE005176; AAK06298.1; -; Genomic_DNA.
DR   PIR; H86899; H86899.
DR   RefSeq; NP_268357.1; NC_002662.1.
DR   RefSeq; WP_010906377.1; NC_002662.1.
DR   AlphaFoldDB; Q9CDL9; -.
DR   SMR; Q9CDL9; -.
DR   PaxDb; 272623-L0118; -.
DR   EnsemblBacteria; AAK06298; AAK06298; L0118.
DR   KEGG; lla:L0118; -.
DR   PATRIC; fig|272623.7.peg.2362; -.
DR   eggNOG; COG0174; Bacteria.
DR   HOGENOM; CLU_017290_1_3_9; -.
DR   OrthoDB; 9807095at2; -.
DR   Proteomes; UP000002196; 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; Reference proteome.
FT   CHAIN           1..446
FT                   /note="Glutamine synthetase"
FT                   /id="PRO_0000153242"
FT   DOMAIN          15..102
FT                   /note="GS beta-grasp"
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU01330"
FT   DOMAIN          109..446
FT                   /note="GS catalytic"
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU01331"
FT   BINDING         133
FT                   /ligand="Mg(2+)"
FT                   /ligand_id="ChEBI:CHEBI:18420"
FT                   /ligand_label="1"
FT                   /evidence="ECO:0000250|UniProtKB:P12425"
FT   BINDING         135
FT                   /ligand="Mg(2+)"
FT                   /ligand_id="ChEBI:CHEBI:18420"
FT                   /ligand_label="2"
FT                   /evidence="ECO:0000250|UniProtKB:P12425"
FT   BINDING         185
FT                   /ligand="ATP"
FT                   /ligand_id="ChEBI:CHEBI:30616"
FT                   /evidence="ECO:0000250|UniProtKB:P9WN39"
FT   BINDING         190
FT                   /ligand="Mg(2+)"
FT                   /ligand_id="ChEBI:CHEBI:18420"
FT                   /ligand_label="2"
FT                   /evidence="ECO:0000250|UniProtKB:P12425"
FT   BINDING         197
FT                   /ligand="Mg(2+)"
FT                   /ligand_id="ChEBI:CHEBI:18420"
FT                   /ligand_label="2"
FT                   /evidence="ECO:0000250|UniProtKB:P12425"
FT   BINDING         241..242
FT                   /ligand="L-glutamate"
FT                   /ligand_id="ChEBI:CHEBI:29985"
FT                   /evidence="ECO:0000250|UniProtKB:P9WN39"
FT   BINDING         242
FT                   /ligand="L-glutamate"
FT                   /ligand_id="ChEBI:CHEBI:29985"
FT                   /evidence="ECO:0000250|UniProtKB:P12425"
FT   BINDING         246
FT                   /ligand="Mg(2+)"
FT                   /ligand_id="ChEBI:CHEBI:18420"
FT                   /ligand_label="1"
FT                   /evidence="ECO:0000250|UniProtKB:P12425"
FT   BINDING         250
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            63
FT                   /note="Important for inhibition by glutamine"
FT                   /evidence="ECO:0000250|UniProtKB:P12425"
SQ   SEQUENCE   446 AA;  49693 MW;  C0A953D5341AD5CF CRC64;
     MTITAADIRR DVKEKDIKFL RLMFTDILGT LKNVEVPATD EQLDKLFENK MMFDGSSIEG
     FVRINESDMY LYPDLDTWIV FPWGDEYGKV AGVICDVYTP EGEPFAGDPR GVLKRNLKSM
     EKLGFKSFNL GPEPEFFLFK LNENDEPTLE VNDKGGYFDL APTDLAGNTR REIVNVLTDL
     GFEVEASHHE VAIGQHEIDF KYANALKACD NIQIFKLVVK TIARKHGLHA TFMAKPVHGI
     NGSGMHCNMS LFTEDGANAF ADPTGDMGLS DVAHSFIAGL LKHAYNFTAI TNPTVNSYKR
     LVPGYEAPVY VAWAGRNRSP LIRVPASRGL STRVELRAVD PTANPYLALA VLLAAGLDGV
     EHKLEAPEAI ESNIYVMTEE ERKAHGITDL PSTLHNAVKA LPEDTIVTEA LGEHVLVNFV
     EAKRIEWASY AQFVSQWEID NYLELY
//