SAR1B_CRIGR
ID SAR1B_CRIGR Reviewed; 198 AA.
AC Q9QVY3;
DT 23-NOV-2004, integrated into UniProtKB/Swiss-Prot.
DT 01-MAY-2000, sequence version 1.
DT 03-AUG-2022, entry version 119.
DE RecName: Full=GTP-binding protein SAR1b {ECO:0000305};
DE Short=Sar1 {ECO:0000303|PubMed:8138575};
GN Name=SAR1B {ECO:0000250|UniProtKB:Q9Y6B6};
GN Synonyms=SAR1 {ECO:0000303|PubMed:8138575}, SARA2;
OS Cricetulus griseus (Chinese hamster) (Cricetulus barabensis griseus).
OC Eukaryota; Metazoa; Chordata; Craniata; Vertebrata; Euteleostomi; Mammalia;
OC Eutheria; Euarchontoglires; Glires; Rodentia; Myomorpha; Muroidea;
OC Cricetidae; Cricetinae; Cricetulus.
OX NCBI_TaxID=10029;
RN [1]
RP NUCLEOTIDE SEQUENCE, FUNCTION, MUTAGENESIS OF THR-39, AND SUBCELLULAR
RP LOCATION.
RC TISSUE=Ovary;
RX PubMed=8138575; DOI=10.1083/jcb.125.1.51;
RA Kuge O., Dascher C., Orci L., Rowe T., Amherdt M., Plutner H.,
RA Ravazzola M., Tanigawa G., Rothman J.E., Balch W.E.;
RT "Sar1 promotes vesicle budding from the endoplasmic reticulum but not Golgi
RT compartments.";
RL J. Cell Biol. 125:51-65(1994).
RN [2]
RP FUNCTION.
RX PubMed=11149932; DOI=10.1083/jcb.152.1.213;
RA Aridor M., Fish K.N., Bannykh S., Weissman J., Roberts T.H.,
RA Lippincott-Schwartz J., Balch W.E.;
RT "The Sar1 GTPase coordinates biosynthetic cargo selection with endoplasmic
RT reticulum export site assembly.";
RL J. Cell Biol. 152:213-229(2001).
RN [3]
RP CRYSTALLIZATION.
RX PubMed=11914501; DOI=10.1107/s090744490200238x;
RA Huang M., Weissman J.T., Wang C., Balch W.E., Wilson I.A.;
RT "Protein engineering for crystallization of the GTPase Sar1 that regulates
RT ER vesicle budding.";
RL Acta Crystallogr. D 58:700-703(2002).
RN [4] {ECO:0007744|PDB:1F6B}
RP X-RAY CRYSTALLOGRAPHY (1.7 ANGSTROMS) OF 10-198 IN COMPLEX WITH GDP,
RP MUTAGENESIS OF PHE-5; 15-VAL--LEU-19 AND THR-158, AND INTERACTION WITH
RP PREB.
RX PubMed=11739406; DOI=10.1083/jcb.200106039;
RA Huang M., Weissman J.T., Beraud-Dufour S., Luan P., Wang C., Chen W.,
RA Aridor M., Wilson I.A., Balch W.E.;
RT "Crystal structure of Sar1-GDP at 1.7 A resolution and the role of the NH2
RT terminus in ER export.";
RL J. Cell Biol. 155:937-948(2001).
CC -!- FUNCTION: GTP-binding protein involved in transport from the
CC endoplasmic reticulum to the Golgi apparatus (PubMed:11149932,
CC PubMed:8138575). Activated by the guanine nucleotide exchange factor
CC PREB (PubMed:11149932, PubMed:8138575). Involved in the selection of
CC the protein cargo and the assembly of the COPII coat complex
CC (PubMed:11149932, PubMed:8138575). Synergizes with the cargo receptor
CC SURF4 to mediate the export of lipoproteins from the endoplasmic
CC reticulum, thereby regulating lipoprotein delivery and the maintenance
CC of lipid homeostasis (By similarity). {ECO:0000250|UniProtKB:Q9Y6B6,
CC ECO:0000269|PubMed:11149932, ECO:0000269|PubMed:8138575}.
CC -!- SUBUNIT: Homodimer (PubMed:11739406). Binds PREB (PubMed:11739406).
CC Part of the COPII coat complex (PubMed:11739406). Binds to the
CC cytoplasmic tails of target proteins in the endoplasmic reticulum
CC (PubMed:11739406). Interacts with SURF4 (By similarity).
CC {ECO:0000250|UniProtKB:Q9Y6B6, ECO:0000269|PubMed:11739406}.
CC -!- SUBCELLULAR LOCATION: Endoplasmic reticulum membrane
CC {ECO:0000269|PubMed:8138575}; Peripheral membrane protein
CC {ECO:0000269|PubMed:8138575}. Golgi apparatus, Golgi stack membrane
CC {ECO:0000269|PubMed:8138575}; Peripheral membrane protein
CC {ECO:0000269|PubMed:8138575}. Note=Associated with the endoplasmic
CC reticulum and Golgi stacks, in particular in the juxta-nuclear Golgi
CC region. {ECO:0000269|PubMed:8138575}.
CC -!- SIMILARITY: Belongs to the small GTPase superfamily. SAR1 family.
CC {ECO:0000305}.
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DR RefSeq; XP_003498539.1; XM_003498491.3.
DR RefSeq; XP_007611226.1; XM_007613036.2.
DR RefSeq; XP_007611227.1; XM_007613037.1.
DR RefSeq; XP_007626894.1; XM_007628704.2.
DR PDB; 1F6B; X-ray; 1.70 A; A/B=1-198.
DR PDB; 2FA9; X-ray; 2.50 A; A/B=10-198.
DR PDB; 2FMX; X-ray; 1.82 A; A/B=10-198.
DR PDBsum; 1F6B; -.
DR PDBsum; 2FA9; -.
DR PDBsum; 2FMX; -.
DR AlphaFoldDB; Q9QVY3; -.
DR SMR; Q9QVY3; -.
DR STRING; 10029.XP_007611226.1; -.
DR Ensembl; ENSCGRT00001020069; ENSCGRP00001015826; ENSCGRG00001016339.
DR GeneID; 100758826; -.
DR KEGG; cge:100758826; -.
DR CTD; 51128; -.
DR eggNOG; KOG0077; Eukaryota.
DR GeneTree; ENSGT00940000160154; -.
DR OMA; FRWVAQY; -.
DR OrthoDB; 1168548at2759; -.
DR EvolutionaryTrace; Q9QVY3; -.
DR GO; GO:0005789; C:endoplasmic reticulum membrane; TAS:Reactome.
DR GO; GO:0032580; C:Golgi cisterna membrane; IEA:UniProtKB-SubCell.
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:0006886; P:intracellular protein transport; IEA:InterPro.
DR GO; GO:0055088; P:lipid homeostasis; ISS:UniProtKB.
DR GO; GO:0042953; P:lipoprotein transport; ISS:UniProtKB.
DR GO; GO:0032368; P:regulation of lipid transport; ISS:UniProtKB.
DR GO; GO:0016192; P:vesicle-mediated transport; IEA:UniProtKB-KW.
DR Gene3D; 3.40.50.300; -; 1.
DR InterPro; IPR027417; P-loop_NTPase.
DR InterPro; IPR005225; Small_GTP-bd_dom.
DR InterPro; IPR006689; Small_GTPase_ARF/SAR.
DR InterPro; IPR006687; Small_GTPase_SAR1.
DR PANTHER; PTHR45684; PTHR45684; 1.
DR Pfam; PF00025; Arf; 1.
DR PRINTS; PR00328; SAR1GTPBP.
DR SMART; SM00178; SAR; 1.
DR SUPFAM; SSF52540; SSF52540; 1.
DR TIGRFAMs; TIGR00231; small_GTP; 1.
DR PROSITE; PS51422; SAR1; 1.
PE 1: Evidence at protein level;
KW 3D-structure; Endoplasmic reticulum; ER-Golgi transport; Golgi apparatus;
KW GTP-binding; Magnesium; Membrane; Metal-binding; Nucleotide-binding;
KW Phosphoprotein; Protein transport; Transport.
FT CHAIN 1..198
FT /note="GTP-binding protein SAR1b"
FT /id="PRO_0000206260"
FT BINDING 34..40
FT /ligand="GTP"
FT /ligand_id="ChEBI:CHEBI:37565"
FT /evidence="ECO:0000269|PubMed:11739406,
FT ECO:0007744|PDB:1F6B"
FT BINDING 34
FT /ligand="Mg(2+)"
FT /ligand_id="ChEBI:CHEBI:18420"
FT /evidence="ECO:0000269|PubMed:11739406,
FT ECO:0007744|PDB:1F6B"
FT BINDING 58
FT /ligand="GDP"
FT /ligand_id="ChEBI:CHEBI:58189"
FT /evidence="ECO:0000269|PubMed:11739406,
FT ECO:0007744|PDB:1F6B"
FT BINDING 75
FT /ligand="GDP"
FT /ligand_id="ChEBI:CHEBI:58189"
FT /evidence="ECO:0000269|PubMed:11739406,
FT ECO:0007744|PDB:1F6B"
FT BINDING 75
FT /ligand="Mg(2+)"
FT /ligand_id="ChEBI:CHEBI:18420"
FT /evidence="ECO:0000269|PubMed:11739406,
FT ECO:0007744|PDB:1F6B"
FT BINDING 134..137
FT /ligand="GTP"
FT /ligand_id="ChEBI:CHEBI:37565"
FT /evidence="ECO:0000269|PubMed:11739406,
FT ECO:0007744|PDB:1F6B"
FT BINDING 180..181
FT /ligand="GTP"
FT /ligand_id="ChEBI:CHEBI:37565"
FT /evidence="ECO:0000269|PubMed:11739406,
FT ECO:0007744|PDB:1F6B"
FT MOD_RES 164
FT /note="Phosphoserine"
FT /evidence="ECO:0000250|UniProtKB:Q9Y6B6"
FT MUTAGEN 5
FT /note="F->D: Decreases recruitment to the endoplasmic
FT reticulum."
FT /evidence="ECO:0000269|PubMed:11739406"
FT MUTAGEN 15..19
FT /note="VLQFL->AAAA: Blocks export of proteins from the ER
FT to the Golgi. No effect on nucleotide binding. Abolishes
FT localization to the endoplasmic reticulum."
FT /evidence="ECO:0000269|PubMed:11739406"
FT MUTAGEN 39
FT /note="T->N: Lowers affinity for GTP, but not for GDP.
FT Inhibits export of proteins from the ER to the Golgi."
FT /evidence="ECO:0000269|PubMed:8138575"
FT MUTAGEN 158
FT /note="T->A: Blocks export of proteins from the ER to the
FT Golgi."
FT /evidence="ECO:0000269|PubMed:11739406"
FT HELIX 14..18
FT /evidence="ECO:0007829|PDB:1F6B"
FT STRAND 26..33
FT /evidence="ECO:0007829|PDB:1F6B"
FT HELIX 38..45
FT /evidence="ECO:0007829|PDB:1F6B"
FT STRAND 62..66
FT /evidence="ECO:0007829|PDB:1F6B"
FT STRAND 69..76
FT /evidence="ECO:0007829|PDB:1F6B"
FT STRAND 79..81
FT /evidence="ECO:0007829|PDB:2FA9"
FT HELIX 85..92
FT /evidence="ECO:0007829|PDB:1F6B"
FT STRAND 94..101
FT /evidence="ECO:0007829|PDB:1F6B"
FT HELIX 105..107
FT /evidence="ECO:0007829|PDB:1F6B"
FT HELIX 108..119
FT /evidence="ECO:0007829|PDB:1F6B"
FT HELIX 122..124
FT /evidence="ECO:0007829|PDB:1F6B"
FT STRAND 129..134
FT /evidence="ECO:0007829|PDB:1F6B"
FT HELIX 144..151
FT /evidence="ECO:0007829|PDB:1F6B"
FT TURN 154..156
FT /evidence="ECO:0007829|PDB:1F6B"
FT TURN 165..167
FT /evidence="ECO:0007829|PDB:1F6B"
FT STRAND 173..177
FT /evidence="ECO:0007829|PDB:1F6B"
FT TURN 180..183
FT /evidence="ECO:0007829|PDB:1F6B"
FT HELIX 186..194
FT /evidence="ECO:0007829|PDB:1F6B"
SQ SEQUENCE 198 AA; 22410 MW; 6056769070CE91FA CRC64;
MSFIFDWIYS GFSSVLQFLG LYKKTGKLVF LGLDNAGKTT LLHMLKDDRL GQHVPTLHPT
SEELTIAGMT FTTFDLGGHI QARRVWKNYL PAINGIVFLV DCADHERLLE SKEELDSLMT
DETIANVPIL ILGNKIDRPE AISEERLREM FGLYGQTTGK GSVSLKELNA RPLEVFMCSV
LKRQGYGEGF RWMAQYID
