ID AEQ1_AEQVI Reviewed; 196 AA. AC P07164; DT 01-APR-1988, integrated into UniProtKB/Swiss-Prot. DT 01-APR-1988, sequence version 1. DT 24-JAN-2024, entry version 117. DE RecName: Full=Aequorin-1; DE Flags: Precursor; OS Aequorea victoria (Water jellyfish) (Mesonema victoria). OC Eukaryota; Metazoa; Cnidaria; Hydrozoa; Hydroidolina; Leptothecata; OC Aequoreidae; Aequorea. OX NCBI_TaxID=6100; RN [1] RP NUCLEOTIDE SEQUENCE [MRNA]. RX PubMed=2882777; DOI=10.1021/bi00379a019; RA Prasher D.C., McCann R.O., Longiaru M., Cormier M.J.; RT "Sequence comparisons of complementary DNAs encoding aequorin isotypes."; RL Biochemistry 26:1326-1332(1987). RN [2] RP PROTEIN SEQUENCE OF 8-196. RX PubMed=2866797; DOI=10.1021/bi00345a006; RA Charbonneau H., Walsh K.A., McCann R.O., Prendergast F.G., Cormier M.J., RA Vanaman T.C.; RT "Amino acid sequence of the calcium-dependent photoprotein aequorin."; RL Biochemistry 24:6762-6771(1985). RN [3] RP MUTAGENESIS OF PRO-196. RX PubMed=1765170; DOI=10.1016/0014-5793(91)81385-l; RA Nomura M., Inouye S., Ohmiya Y., Tsuji F.I.; RT "A C-terminal proline is required for bioluminescence of the Ca(2+)-binding RT photoprotein, aequorin."; RL FEBS Lett. 295:63-66(1991). RN [4] RP PRELIMINARY DISULFIDE BOND. RX PubMed=8405461; DOI=10.1016/0014-5793(93)80637-a; RA Ohmiya Y., Kurono S., Ohashi M., Fagan T.F., Tsuji F.I.; RT "Mass spectrometric evidence for a disulfide bond in aequorin RT regeneration."; RL FEBS Lett. 332:226-228(1993). RN [5] RP X-RAY CRYSTALLOGRAPHY (1.7 ANGSTROMS) OF 7-196 IN COMPLEX WITH CALCIUM RP IONS. RX PubMed=15689515; DOI=10.1110/ps.041142905; RA Deng L., Vysotski E.S., Markova S.V., Liu Z.-J., Lee J., Rose J., RA Wang B.-C.; RT "All three Ca2+-binding loops of photoproteins bind calcium ions: the RT crystal structures of calcium-loaded apo-aequorin and apo-obelin."; RL Protein Sci. 14:663-675(2005). CC -!- FUNCTION: Ca(2+)-dependent bioluminescence photoprotein. Displays an CC emission peak at 470 nm (blue light). Trace amounts of calcium ion CC trigger the intramolecular oxidation of the chromophore, coelenterazine CC into coelenteramide and CO(2) with the concomitant emission of light. CC -!- PTM: The reduction of the disulfide bond is necessary to regenerate CC aequorin from apoaequorin. CC -!- BIOTECHNOLOGY: Aequorin is used as an intracellular Ca(2+) indicator. CC Aequorin has a number of advantages over other Ca(2+) indicators, for CC example, low leakage rate from cells, lack of intracellular CC compartmentalization or sequestration and it does not disrupt cell CC functions or embryo development. CC -!- SIMILARITY: Belongs to the aequorin family. {ECO:0000305}. CC -!- CAUTION: Was originally thought to have an internal disulfide bond. CC {ECO:0000305|PubMed:8405461}. CC -!- WEB RESOURCE: Name=Wikipedia; Note=Aequorin entry; CC URL="https://en.wikipedia.org/wiki/Aequorin"; 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; M16103; AAA27716.1; -; mRNA. DR PIR; A26623; A26623. DR PDB; 1SL8; X-ray; 1.70 A; A=7-196. DR PDBsum; 1SL8; -. DR AlphaFoldDB; P07164; -. DR SMR; P07164; -. DR TCDB; 8.A.82.5.1; the calmodulin calcium binding protein (calmodulin) family. DR KEGG; ag:AAA27716; -. DR BioCyc; MetaCyc:MONOMER-20288; -. DR BRENDA; 1.13.12.24; 8923. DR BRENDA; 1.13.12.5; 8923. DR EvolutionaryTrace; P07164; -. DR GO; GO:0005509; F:calcium ion binding; IEA:InterPro. DR GO; GO:0008218; P:bioluminescence; IEA:UniProtKB-KW. DR CDD; cd00051; EFh; 1. DR Gene3D; 1.10.238.10; EF-hand; 1. DR InterPro; IPR011992; EF-hand-dom_pair. DR InterPro; IPR018247; EF_Hand_1_Ca_BS. DR InterPro; IPR002048; EF_hand_dom. DR Pfam; PF13202; EF-hand_5; 1. DR Pfam; PF13499; EF-hand_7; 1. DR SMART; SM00054; EFh; 3. DR SUPFAM; SSF47473; EF-hand; 1. DR PROSITE; PS00018; EF_HAND_1; 3. DR PROSITE; PS50222; EF_HAND_2; 3. PE 1: Evidence at protein level; KW 3D-structure; Calcium; Direct protein sequencing; Disulfide bond; KW Luminescence; Metal-binding; Photoprotein; Repeat. FT PROPEP 1..7 FT /evidence="ECO:0000269|PubMed:2866797" FT /id="PRO_0000004126" FT CHAIN 8..196 FT /note="Aequorin-1" FT /id="PRO_0000004127" FT DOMAIN 18..53 FT /note="EF-hand 1" FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00448" FT DOMAIN 54..108 FT /note="EF-hand 2" FT /evidence="ECO:0000305" FT DOMAIN 111..146 FT /note="EF-hand 3" FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00448" FT DOMAIN 147..182 FT /note="EF-hand 4" FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00448" FT REGION 47..57 FT /note="May interact with the chromophore" FT REGION 62..72 FT /note="May interact with the chromophore" FT REGION 107..117 FT /note="May interact with the chromophore" FT BINDING 31 FT /ligand="Ca(2+)" FT /ligand_id="ChEBI:CHEBI:29108" FT /ligand_label="1" FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00448" FT BINDING 33 FT /ligand="Ca(2+)" FT /ligand_id="ChEBI:CHEBI:29108" FT /ligand_label="1" FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00448" FT BINDING 35 FT /ligand="Ca(2+)" FT /ligand_id="ChEBI:CHEBI:29108" FT /ligand_label="1" FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00448" FT BINDING 37 FT /ligand="Ca(2+)" FT /ligand_id="ChEBI:CHEBI:29108" FT /ligand_label="1" FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00448" FT BINDING 42 FT /ligand="Ca(2+)" FT /ligand_id="ChEBI:CHEBI:29108" FT /ligand_label="1" FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00448" FT BINDING 124 FT /ligand="Ca(2+)" FT /ligand_id="ChEBI:CHEBI:29108" FT /ligand_label="2" FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00448" FT BINDING 126 FT /ligand="Ca(2+)" FT /ligand_id="ChEBI:CHEBI:29108" FT /ligand_label="2" FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00448" FT BINDING 128 FT /ligand="Ca(2+)" FT /ligand_id="ChEBI:CHEBI:29108" FT /ligand_label="2" FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00448" FT BINDING 135 FT /ligand="Ca(2+)" FT /ligand_id="ChEBI:CHEBI:29108" FT /ligand_label="2" FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00448" FT BINDING 160 FT /ligand="Ca(2+)" FT /ligand_id="ChEBI:CHEBI:29108" FT /ligand_label="3" FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00448" FT BINDING 162 FT /ligand="Ca(2+)" FT /ligand_id="ChEBI:CHEBI:29108" FT /ligand_label="3" FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00448" FT BINDING 164 FT /ligand="Ca(2+)" FT /ligand_id="ChEBI:CHEBI:29108" FT /ligand_label="3" FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00448" FT BINDING 166 FT /ligand="Ca(2+)" FT /ligand_id="ChEBI:CHEBI:29108" FT /ligand_label="3" FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00448" FT BINDING 171 FT /ligand="Ca(2+)" FT /ligand_id="ChEBI:CHEBI:29108" FT /ligand_label="3" FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00448" FT MUTAGEN 196 FT /note="Missing: Loss of bioluminescence." FT /evidence="ECO:0000269|PubMed:1765170" FT HELIX 17..30 FT /evidence="ECO:0007829|PDB:1SL8" FT STRAND 35..39 FT /evidence="ECO:0007829|PDB:1SL8" FT HELIX 40..53 FT /evidence="ECO:0007829|PDB:1SL8" FT HELIX 59..75 FT /evidence="ECO:0007829|PDB:1SL8" FT STRAND 83..85 FT /evidence="ECO:0007829|PDB:1SL8" FT HELIX 86..105 FT /evidence="ECO:0007829|PDB:1SL8" FT HELIX 111..123 FT /evidence="ECO:0007829|PDB:1SL8" FT STRAND 128..131 FT /evidence="ECO:0007829|PDB:1SL8" FT HELIX 133..142 FT /evidence="ECO:0007829|PDB:1SL8" FT HELIX 149..159 FT /evidence="ECO:0007829|PDB:1SL8" FT STRAND 165..167 FT /evidence="ECO:0007829|PDB:1SL8" FT HELIX 169..180 FT /evidence="ECO:0007829|PDB:1SL8" FT HELIX 190..193 FT /evidence="ECO:0007829|PDB:1SL8" SQ SEQUENCE 196 AA; 22514 MW; 9AA5B636288A5B8F CRC64; MTSEQYSVKL TPDFDNPKWI GRHKHMFNFL DVNHNGRISL DEMVYKASDI VINNLGATPE QAKRHKDAVE AFFGGAGMKY GVETEWPEYI EGWKRLASEE LKRYSKNQIT LIRLWGDALF DIIDKDQNGA ISLDEWKAYT KSDGIIQSSE DCEETFRVCD IDESGQLDVD EMTRQHLGFW YTMDPACEKL YGGAVP //