Q27709 (OBL_OBELO) Reviewed, UniProtKB/Swiss-Prot

Names and origin

Protein names	Recommended name: Obelin Short name=OBL
Organism	Obelia longissima (Black sea hydrozoan) (Laomedea longissima)
Taxonomic identifier	32570 [NCBI]
Taxonomic lineage	cellular organisms › Eukaryota › Opisthokonta › Metazoa › Eumetazoa › Cnidaria › Hydrozoa › Hydroida › Leptomedusae › Campanulariidae › Obelia

Protein attributes

Sequence length	195 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.
Sequence similarities	Belongs to the aequorin family. Contains 4 EF-hand domains.

Ontologies

Keywords
Biological process	Luminescence
Domain	Repeat
Ligand	Calcium Metal-binding
Molecular function	Photoprotein
Technical term	3D-structure
Gene Ontology (GO)
Biological_process	bioluminescence Inferred from electronic annotation. Source: UniProtKB-KW
Molecular_function	calcium ion binding Inferred from electronic annotation. Source: InterPro
Complete GO annotation...

Sequence annotation (Features)

Feature key

Position(s)

Length

Description

Graphical view

Feature identifier

Molecule processing

Propeptide

1 – 6

6

Potential

PRO_0000004136

Chain

7 – 195

189

Obelin

PRO_0000004137

Regions

Domain

17 – 52

36

EF-hand 1

Domain

53 – 88

36

EF-hand 2

Domain

110 – 145

36

EF-hand 3

Domain

146 – 181

36

EF-hand 4

Calcium binding

30 – 41

12

1 Potential

Calcium binding

123 – 134

12

2 Potential

Calcium binding

159 – 170

12

3 Potential

Experimental info

Mutagenesis

92

1

W → F: Shifts luminescence to violet by adding a new band at 410 nm. Ref.4

Secondary structure

1

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195

Helix Strand Turn

Details...

Helix

3 – 5

3

Helix

16 – 29

14

Beta strand

33 – 35

3

Helix

39 – 48

10

Helix

50 – 53

4

Helix

58 – 74

17

Beta strand

82 – 84

3

Helix

85 – 104

20

Helix

110 – 121

12

Beta strand

124 – 126

3

Beta strand

128 – 130

3

Helix

132 – 142

11

Helix

148 – 157

10

Beta strand

163 – 166

4

Helix

168 – 179

12

Helix

184 – 186

3

Turn

187 – 192

6

Sequences

	Sequence		Length	Mass (Da)
	Q27709 [UniParc]. Last modified November 1, 1997. Version 1. Checksum: 5D002270B73D3663	FASTA	195	22,226
	10 20 30 40 50 60 MSSKYAVKLK TDFDNPRWIK RHKHMFDFLD INGNGKITLD EIVSKASDDI CAKLEATPEQ 70 80 90 100 110 120 TKRHQVCVEA FFRGCGMEYG KEIAFPQFLD GWKQLATSEL KKWARNEPTL IREWGDAVFD 130 140 150 160 170 180 IFDKDGSGTI TLDEWKAYGK ISGISPSQED CEATFRHCDL DNSGDLDVDE MTRQHLGFWY 190 TLDPEADGLY GNGVP

References

[1]	"Sequence of the cDNA encoding the Ca(2+)-activated photoprotein obelin from the hydroid polyp Obelia longissima." Illarionov B.A., Bondar V.S., Illarionova V.A., Vysotski E.S. Gene 153:273-274(1995) [PubMed] [Europe PMC] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [MRNA].
[2]	"Structure of the Ca2+-regulated photoprotein obelin at 1.7 A resolution determined directly from its sulfur substructure." Liu Z.J., Vysotski E.S., Chen C.J., Rose J.P., Lee J., Wang B.C. Protein Sci. 9:2085-2093(2000) [PubMed] [Europe PMC] [Abstract] Cited for: X-RAY CRYSTALLOGRAPHY (1.73 ANGSTROMS).
[3]	"Atomic resolution structure of obelin: soaking with calcium enhances electron density of the second oxygen atom substituted at the C2-position of coelenterazine." Liu Z.J., Vysotski E.S., Deng L., Lee J., Rose J., Wang B.C. Biochem. Biophys. Res. Commun. 311:433-439(2003) [PubMed] [Europe PMC] [Abstract] Cited for: X-RAY CRYSTALLOGRAPHY (1.1 ANGSTROMS).
[4]	"Crystal structure of a Ca2+-discharged photoprotein: implications for mechanisms of the calcium trigger and bioluminescence." Deng L., Markova S.V., Vysotski E.S., Liu Z.J., Lee J., Rose J., Wang B.C. J. Biol. Chem. 279:33647-33652(2004) [PubMed] [Europe PMC] [Abstract] Cited for: X-RAY CRYSTALLOGRAPHY (1.96 ANGSTROMS), MUTAGENESIS OF TRP-92.
+	Additional computationally mapped references.

Cross-references

Sequence databases

EMBL
GenBank
DDBJ

U07128 mRNA. Translation: AAA67708.1.

3D structure databases

PDBe
RCSB PDB
PDBj

Entry	Method	Resolution (Å)	Chain	Positions	PDBsum
1EL4	X-ray	1.73	A	1-195	[»]
1JF0	X-ray	1.82	A	3-195	[»]
1JF2	X-ray	1.72	A	1-195	[»]
1QV0	X-ray	1.10	A	1-195	[»]
1QV1	X-ray	1.10	A	1-195	[»]
1S36	X-ray	1.96	A	1-195	[»]
1SL7	X-ray	2.20	A	1-195	[»]
1SL9	X-ray	1.17	A	1-195	[»]
2F8P	X-ray	1.93	A	3-195	[»]

ProteinModelPortal

Q27709.

SMR

Q27709. Positions 2-195.

ModBase

Search...

Protocols and materials databases

StructuralBiologyKnowledgebase

Search...

Family and domain databases

Gene3D

1.10.238.10. 1 hit.

InterPro

IPR011992. EF-hand-like_dom.
IPR018247. EF_Hand_1_Ca_BS.
IPR002048. EF_hand_dom.
[Graphical view]

Pfam

PF13202. EF_hand_3. 1 hit.
PF13499. EF_hand_5. 1 hit.
[Graphical view]

SMART

SM00054. EFh. 3 hits.
[Graphical view]

PROSITE

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

ProtoNet

Search...

Other

EvolutionaryTrace

Q27709.

Entry information

Entry name

OBL_OBELO

Accession

Primary (citable) accession number: Q27709

Entry history

Integrated into UniProtKB/Swiss-Prot:	November 1, 1997
Last sequence update:	November 1, 1997
Last modified:	May 1, 2013
This is version 72 of the entry and version 1 of the sequence. [Complete history]

Entry status

Reviewed (UniProtKB/Swiss-Prot)