Q8AXN9 · RPE65_CYNPY
- ProteinRetinoid isomerohydrolase
- GeneRPE65
- StatusUniProtKB reviewed (Swiss-Prot)
- Amino acids533 (go to sequence)
- Protein existenceEvidence at transcript level
- Annotation score5/5
Function
function
Critical isomerohydrolase in the retinoid cycle involved in regeneration of 11-cis-retinal, the chromophore of rod and cone opsins. Catalyzes the cleavage and isomerization of all-trans-retinyl fatty acid esters to 11-cis-retinol which is further oxidized by 11-cis retinol dehydrogenase to 11-cis-retinal for use as visual chromophore. Essential for the production of 11-cis retinal for both rod and cone photoreceptors. Also capable of catalyzing the isomerization of lutein to meso-zeaxanthin an eye-specific carotenoid. The soluble form binds vitamin A (all-trans-retinol), making it available for LRAT processing to all-trans-retinyl ester. The membrane form, palmitoylated by LRAT, binds all-trans-retinyl esters, making them available for IMH (isomerohydrolase) processing to all-cis-retinol. The soluble form is regenerated by transferring its palmitoyl groups onto 11-cis-retinol, a reaction catalyzed by LRAT.
Catalytic activity
- an all-trans-retinyl ester + H2O = 11-cis-retinol + a fatty acid + H+
Cofactor
Note: Binds 1 Fe2+ ion per subunit.
Features
Showing features for binding site.
GO annotations
Aspect | Term | |
---|---|---|
Cellular Component | endoplasmic reticulum membrane | |
Cellular Component | membrane | |
Cellular Component | plasma membrane | |
Molecular Function | all-trans-retinyl-ester hydrolase, 11-cis retinol forming activity | |
Molecular Function | all-trans-retinyl-palmitate hydrolase, 11-cis retinol forming activity | |
Molecular Function | beta-carotene 15,15'-dioxygenase activity | |
Molecular Function | cardiolipin binding | |
Molecular Function | isomerase activity | |
Molecular Function | metal ion binding | |
Molecular Function | phosphatidylcholine binding | |
Molecular Function | phosphatidylserine binding | |
Molecular Function | retinol isomerase activity | |
Biological Process | retinal metabolic process | |
Biological Process | retinoid metabolic process | |
Biological Process | visual perception | |
Biological Process | zeaxanthin biosynthetic process |
Keywords
- Molecular function
- Biological process
- Ligand
Enzyme and pathway databases
Names & Taxonomy
Protein names
- Recommended nameRetinoid isomerohydrolase
- EC number
- Alternative names
Gene names
Organism names
- Taxonomic lineageEukaryota > Metazoa > Chordata > Craniata > Vertebrata > Euteleostomi > Amphibia > Batrachia > Caudata > Salamandroidea > Salamandridae > Pleurodelinae > Cynops
Accessions
- Primary accessionQ8AXN9
Subcellular Location
PTM/Processing
Features
Showing features for initiator methionine, modified residue, chain, lipidation.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Initiator methionine | 1 | Removed | ||||
Sequence: M | ||||||
Modified residue | 2 | N-acetylserine | ||||
Sequence: S | ||||||
Chain | PRO_0000143948 | 2-533 | Retinoid isomerohydrolase | |||
Sequence: SSKVEHPAGGYKKLFETVEELASPITAHVTGRIPVWLTGSLLRCGPGLFEVGSEQFYHLFDGQALLHKFDFKEGHVTYHRRFIRTDTYVRAMTEKRIVITEFGTFAFPDPCKNIFSRFLSYFQGLEVTDNTLVNVYPVGEDYYACTETNYITKVNPETLETIKKVDLCNYVSINGVTAHPLIENDGTVYNIGNCFGKHFSFAYNIVKIPPLQEDKEDPINKAKVVVQFPCSERFKPSYVHSFGLTPNYIVFVEQPVKINLFKFLSSWSIWGANYMDCFESHETMGVWMHVAEKLTGEYLNIKYRTSAFNLFHHINTYEDHGFLIVDLCCWKGFEFIYNYLYLANMRENWEEVKRNAEKAPQPEVRRYVLPLDIHKVDTGKNLVNLPYTTATAILRSDETIWLEPEVLFSGPRLAFEFPQINYKKFGGKDYTFAYGLGLNHFVPDRLSKLNVKTKEIWVWQEPDSYPSEPIFVSQPDAMEEDDGVVLSVIVNPGPGQKPAFLLILNAKDMSEIARAEVDINIPVTFHGMYKKA | ||||||
Lipidation | 112 | S-palmitoyl cysteine; in membrane form | ||||
Sequence: C | ||||||
Lipidation | 231 | S-palmitoyl cysteine; in membrane form | ||||
Sequence: C | ||||||
Lipidation | 329 | S-palmitoyl cysteine; in membrane form | ||||
Sequence: C | ||||||
Lipidation | 330 | S-palmitoyl cysteine; in membrane form | ||||
Sequence: C |
Post-translational modification
Palmitoylation by LRAT regulates ligand binding specificity; the palmitoylated form (membrane form) specifically binds all-trans-retinyl-palmitate, while the soluble unpalmitoylated form binds all-trans-retinol (vitamin A).
Keywords
- PTM
Expression
Tissue specificity
Retinal pigment epithelium specific.
Structure
Family & Domains
Sequence
- Sequence statusComplete
- Length533
- Mass (Da)61,264
- Last updated2007-01-23 v3
- Checksum3C9610539122F29D