Reviewed, UniProtKB/Swiss-Prot P07164 (AEQ1_AEQVI)

Names and origin

Protein names	Recommended name:     Aequorin-1
Organism	Aequorea victoria (Jellyfish)
Taxonomic identifier	6100 [NCBI]
Taxonomic lineage	Eukaryota › Metazoa › Cnidaria › Hydrozoa › Hydroida › Leptomedusae › Aequoreidae › Aequorea

Protein attributes

Sequence length	196 AA.
Sequence status	Complete.
Sequence processing	The displayed sequence is further processed into a mature form.
Protein existence	Evidence at protein level.

General annotation (Comments)

Function	Ca2+-dependent bioluminescence photoprotein. Displays an emission peak at 470 nm (blue light). Trace amounts of calcium ion trigger the intramolecular oxidation of the chromophore, coelenterazine into coelenteramide and CO2 with the concomitant emission of light.
Post-translational modification	The reduction of the disulfide bond is necessary to regenerate aequorin from apoaequorin.
Biotechnological use	Aequorin is used as an intracellular Ca2+ indicator. Aequorin has a number of advantages over other Ca2+ indicators, for example, low leakage rate from cells, lack of intracellular compartmentalization or sequestration and it does not disrupt cell functions or embryo development.
Sequence similarities	Belongs to the aequorin family. Contains 4 EF-hand domains.
Caution	Was originally (Ref.4) thought to have a internal disulfide bond.

Ontologies

Keywords
Biological process	Luminescence
Domain	Repeat
Ligand	Calcium
Molecular function	Photoprotein
PTM	Disulfide bond
Technical term	3D-structure Direct protein sequencing
Gene Ontology (GO)
Biological process	bioluminescence Inferred from electronic annotation. Source: UniProtKB-KW
Molecular function	calcium ion binding Inferred from electronic annotation. Source: UniProtKB-KW
Complete GO annotation...

Sequence annotation (Features)

Feature key

Position(s)

Length

Description

Graphical view

Feature identifier

Molecule processing

Propeptide

1 – 7

7

PRO_0000004126

Chain

8 – 196

189

Aequorin-1

PRO_0000004127

Regions

Domain

18 – 53

36

EF-hand 1

Domain

54 – 108

55

EF-hand 2

Domain

111 – 146

36

EF-hand 3

Domain

147 – 182

36

EF-hand 4

Calcium binding

31 – 42

12

1

Calcium binding

124 – 135

12

2

Calcium binding

160 – 171

12

3

Region

47 – 57

11

May interact with the chromophore

Region

62 – 72

11

May interact with the chromophore

Region

107 – 117

11

May interact with the chromophore

Experimental info

Mutagenesis

196

1

Missing: Loss of bioluminescence. Ref.3

Secondary structure

1

.

.

.

.

.

.

.

.

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.

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.

.

.

.

.

.

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.

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.

.

.

196

Helix Strand Turn

Details...

Helix

17 – 30

14

Beta strand

35 – 39

5

Helix

40 – 53

14

Helix

59 – 75

17

Beta strand

83 – 85

3

Helix

86 – 105

20

Helix

111 – 123

13

Beta strand

128 – 131

4

Helix

133 – 142

10

Helix

149 – 159

11

Beta strand

165 – 167

3

Helix

169 – 180

12

Helix

190 – 193

4

Sequences

	Sequence		Length	Mass (Da)
	P07164-1 [UniParc]. Last modified April 1, 1988. Version 1. Checksum: 9AA5B636288A5B8F	FASTA	196	22,514
	10 20 30 40 50 60 MTSEQYSVKL TPDFDNPKWI GRHKHMFNFL DVNHNGRISL DEMVYKASDI VINNLGATPE 70 80 90 100 110 120 QAKRHKDAVE AFFGGAGMKY GVETEWPEYI EGWKRLASEE LKRYSKNQIT LIRLWGDALF 130 140 150 160 170 180 DIIDKDQNGA ISLDEWKAYT KSDGIIQSSE DCEETFRVCD IDESGQLDVD EMTRQHLGFW 190 YTMDPACEKL YGGAVP

References

[1]	"Sequence comparisons of complementary DNAs encoding aequorin isotypes." Prasher D.C., McCann R.O., Longiaru M., Cormier M.J. Biochemistry 26:1326-1332(1987) [PubMed: 2882777] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [MRNA].
[2]	"Amino acid sequence of the calcium-dependent photoprotein aequorin." Charbonneau H., Walsh K.A., McCann R.O., Prendergast F.G., Cormier M.J., Vanaman T.C. Biochemistry 24:6762-6771(1985) [PubMed: 2866797] [Abstract] Cited for: PROTEIN SEQUENCE OF 8-196.
[3]	"A C-terminal proline is required for bioluminescence of the Ca(2+)-binding photoprotein, aequorin." Nomura M., Inouye S., Ohmiya Y., Tsuji F.I. FEBS Lett. 295:63-66(1991) [PubMed: 1765170] [Abstract] Cited for: MUTAGENESIS OF PRO-196.
[4]	"Mass spectrometric evidence for a disulfide bond in aequorin regeneration." Ohmiya Y., Kurono S., Ohashi M., Fagan T.F., Tsuji F.I. FEBS Lett. 332:226-228(1993) [PubMed: 8405461] [Abstract] Cited for: PRELIMINARY DISULFIDE BOND.
[5]	"All three Ca2+-binding loops of photoproteins bind calcium ions: the crystal structures of calcium-loaded apo-aequorin and apo-obelin." Deng L., Vysotski E.S., Markova S.V., Liu Z.-J., Lee J., Rose J., Wang B.-C. Protein Sci. 14:663-675(2005) [PubMed: 15689515] [Abstract] Cited for: X-RAY CRYSTALLOGRAPHY (1.7 ANGSTROMS) OF 7-196 IN COMPLEX WITH CALCIUM IONS.

Web resources

Wikipedia

Aequorin entry

Cross-references

Sequence databases

EMBLGenBankDDBJ

M16103 mRNA. Translation: AAA27716.1.

PIR

A26623.

3D structure databases

PDBPDBe

Entry	Method	Resolution (Å)	Chain	Positions	PDBsum
1SL8	X-ray	1.70	A	7-196	[»]

ModBase

Search...

Enzyme and pathway databases

BRENDA

1.13.12.5. 280134.

Family and domain databases

InterPro

IPR011992. EF-Hand_type.
IPR018248. EF_hand.
IPR018247. EF_HAND_1_Ca_BS.
IPR018249. EF_HAND_2.
IPR002048. EF_hand_Ca_bd.
[Graphical view]

Gene3D

G3DSA:1.10.238.10. EF-Hand_type. 1 hit.

Pfam

PF00036. efhand. 1 hit.
[Graphical view]

ProDom

PD000012. EF-hand. 1 hit.
[Graphical view] [Entries sharing at least one domain]

SMART

SM00054. EFh. 3 hits.
[Graphical view]

PROSITE

PS00018. EF_HAND_1. 3 hits.
PS50222. EF_HAND_2. 3 hits.
[Graphical view]

ProtoNet

Search...

Entry information

Entry name

AEQ1_AEQVI

Accession

Primary (citable) accession number: P07164

Entry history

Integrated into UniProtKB/Swiss-Prot:	April 1, 1988
Last sequence update:	April 1, 1988
Last modified:	September 22, 2009
This is version 74 of the entry and version 1 of the sequence. [Complete history]

Entry status

Reviewed (UniProtKB/Swiss-Prot)