ID   GNAI_HOMAM              Reviewed;         355 AA.
AC   P41776;
DT   01-NOV-1995, integrated into UniProtKB/Swiss-Prot.
DT   23-JAN-2007, sequence version 2.
DT   03-AUG-2022, entry version 98.
DE   RecName: Full=Guanine nucleotide-binding protein G(i) subunit alpha;
DE   AltName: Full=Adenylate cyclase-inhibiting G alpha protein;
OS   Homarus americanus (American lobster).
OC   Eukaryota; Metazoa; Ecdysozoa; Arthropoda; Crustacea; Multicrustacea;
OC   Malacostraca; Eumalacostraca; Eucarida; Decapoda; Pleocyemata; Astacidea;
OC   Nephropoidea; Nephropidae; Homarus.
OX   NCBI_TaxID=6706;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [MRNA].
RC   TISSUE=Olfactory organ;
RX   PubMed=1279345; DOI=10.1016/0169-328x(92)90183-c;
RA   McClintock T.S., Byrnes A.P., Lerner M.R.;
RT   "Molecular cloning of a G-protein alpha i subunit from the lobster
RT   olfactory organ.";
RL   Brain Res. Mol. Brain Res. 14:273-276(1992).
CC   -!- FUNCTION: Guanine nucleotide-binding proteins (G proteins) are involved
CC       as modulators or transducers in various transmembrane signaling
CC       systems.
CC   -!- SUBUNIT: G proteins are composed of 3 units; alpha, beta and gamma. The
CC       alpha chain contains the guanine nucleotide binding site.
CC   -!- SIMILARITY: Belongs to the G-alpha family. G(i/o/t/z) subfamily.
CC       {ECO:0000305}.
CC   ---------------------------------------------------------------------------
CC   Copyrighted by the UniProt Consortium, see https://www.uniprot.org/terms
CC   Distributed under the Creative Commons Attribution (CC BY 4.0) License
CC   ---------------------------------------------------------------------------
DR   EMBL; S47614; AAB24072.2; ALT_SEQ; mRNA.
DR   PIR; A48976; A48976.
DR   AlphaFoldDB; P41776; -.
DR   SMR; P41776; -.
DR   GO; GO:0110165; C:cellular anatomical entity; IEA:UniProt.
DR   GO; GO:0031683; F:G-protein beta/gamma-subunit complex binding; IEA:InterPro.
DR   GO; GO:0005525; F:GTP binding; IEA:UniProtKB-KW.
DR   GO; GO:0003924; F:GTPase activity; IEA:InterPro.
DR   GO; GO:0046872; F:metal ion binding; IEA:UniProtKB-KW.
DR   GO; GO:0007188; P:adenylate cyclase-modulating G protein-coupled receptor signaling pathway; IEA:InterPro.
DR   CDD; cd00066; G-alpha; 1.
DR   Gene3D; 1.10.400.10; -; 1.
DR   Gene3D; 3.40.50.300; -; 1.
DR   InterPro; IPR001408; Gprotein_alpha_I.
DR   InterPro; IPR001019; Gprotein_alpha_su.
DR   InterPro; IPR011025; GproteinA_insert.
DR   InterPro; IPR027417; P-loop_NTPase.
DR   PANTHER; PTHR10218; PTHR10218; 1.
DR   Pfam; PF00503; G-alpha; 1.
DR   PRINTS; PR00318; GPROTEINA.
DR   PRINTS; PR00441; GPROTEINAI.
DR   SMART; SM00275; G_alpha; 1.
DR   SUPFAM; SSF47895; SSF47895; 1.
DR   SUPFAM; SSF52540; SSF52540; 1.
DR   PROSITE; PS51882; G_ALPHA; 1.
PE   2: Evidence at transcript level;
KW   GTP-binding; Lipoprotein; Magnesium; Metal-binding; Myristate;
KW   Nucleotide-binding; Palmitate; Transducer.
FT   INIT_MET        1
FT                   /note="Removed"
FT                   /evidence="ECO:0000250"
FT   CHAIN           2..355
FT                   /note="Guanine nucleotide-binding protein G(i) subunit
FT                   alpha"
FT                   /id="PRO_0000203687"
FT   DOMAIN          33..355
FT                   /note="G-alpha"
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU01230"
FT   REGION          36..49
FT                   /note="G1 motif"
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU01230"
FT   REGION          174..182
FT                   /note="G2 motif"
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU01230"
FT   REGION          197..206
FT                   /note="G3 motif"
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU01230"
FT   REGION          266..273
FT                   /note="G4 motif"
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU01230"
FT   REGION          325..330
FT                   /note="G5 motif"
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU01230"
FT   BINDING         41..48
FT                   /ligand="GTP"
FT                   /ligand_id="ChEBI:CHEBI:37565"
FT                   /evidence="ECO:0000250"
FT   BINDING         48
FT                   /ligand="Mg(2+)"
FT                   /ligand_id="ChEBI:CHEBI:18420"
FT                   /evidence="ECO:0000250"
FT   BINDING         176..182
FT                   /ligand="GTP"
FT                   /ligand_id="ChEBI:CHEBI:37565"
FT                   /evidence="ECO:0000250"
FT   BINDING         182
FT                   /ligand="Mg(2+)"
FT                   /ligand_id="ChEBI:CHEBI:18420"
FT                   /evidence="ECO:0000250"
FT   BINDING         201..205
FT                   /ligand="GTP"
FT                   /ligand_id="ChEBI:CHEBI:37565"
FT                   /evidence="ECO:0000250"
FT   BINDING         270..273
FT                   /ligand="GTP"
FT                   /ligand_id="ChEBI:CHEBI:37565"
FT                   /evidence="ECO:0000250"
FT   BINDING         327
FT                   /ligand="GTP"
FT                   /ligand_id="ChEBI:CHEBI:37565"
FT                   /evidence="ECO:0000250"
FT   LIPID           2
FT                   /note="N-myristoyl glycine"
FT                   /evidence="ECO:0000255"
FT   LIPID           3
FT                   /note="S-palmitoyl cysteine"
FT                   /evidence="ECO:0000255"
FT   CONFLICT        309..324
FT                   /note="Missing (in Ref. 1; AAB24072)"
FT                   /evidence="ECO:0000305"
SQ   SEQUENCE   355 AA;  40732 MW;  CA08F529454C3C4A CRC64;
     MGCAMSNAAD KEAAERSKKI DKDLRLAGER AAREVKLLLL GAGESGKSTI VKQMKIIHET
     GYSREECEQY RPVVYSNTIQ SLMAIIRAMG QLKIDFRDSS RADDARHFFT LASAADEGEL
     TPELANIMKR LWNESGVQHC RNRSREYQLN DTAAYYLNAL DRIARPGYIP TQQDVLRTRV
     KTTGIVETNF SFKNLNFKLF DVGGQRSERK KWIHCFEGVT AIIFVVALSG YDLVLAEDEE
     MNRMIESMKL FDSICNNKWF VETSIILFLN KKDLFEQKIT KSPLTICFPE YQGSNVYEDS
     ANYIRMKFEN LNKRKDQKEI YTHFTCATDT NNIQFVFDAV TDVIIKNNLK DCGLF