Phycourobilin

title: "Phycourobilin" type: doc version: 1 created: 2026-02-28 author: "Wikipedia contributors" status: active scope: public tags: ["photosynthetic-pigments", "tetrapyrroles"] topic_path: "general/photosynthetic-pigments" source: "https://en.wikipedia.org/wiki/Phycourobilin" license: "CC BY-SA 4.0" wikipedia_page_id: 0 wikipedia_revision_id: 0
| ImageFile=phycourobilin.png | ImageSize=200px | ImageFile1 = Phycourobilin 3D.png | ImageSize1=150px | IUPACName=3-[2-[(Z)-[3-(2-carboxyethyl)-5-[ [(2R)-4-ethyl-3-methyl-5-oxo-1,2-dihydropyrrol-2-yl]methyl]-4-methyl-2-pyrrolylidene]methyl]-5-[ [(2S)-3-ethyl-4-methyl-5-oxo-1,2-dihydropyrrol-2-yl]methyl]-4-methyl-1H-pyrrol-3-yl]propanoic acid | OtherNames= |Section1={{Chembox Identifiers | CASNo_Ref = | CASNo= 121734-26-7 | UNII_Ref = | UNII = 446YNT6QXL | PubChem=5289229 | SMILES=CCC1=C(C(=O)N[C@H]1CC2=C(C(=C(N2)\C=C/3\C(=C(C(=N3)C[C@@H]4C(=C(C(=O)N4)CC)C)C)CCC(=O)O)CCC(=O)O)C)C | ChemSpiderID_Ref = | ChemSpiderID = 4451232 | InChI = 1/C33H42N4O6/c1-7-20-19(6)32(42)37-27(20)14-25-18(5)23(10-12-31(40)41)29(35-25)15-28-22(9-11-30(38)39)17(4)24(34-28)13-26-16(3)21(8-2)33(43)36-26/h15,26-27,35H,7-14H2,1-6H3,(H,36,43)(H,37,42)(H,38,39)(H,40,41)/b28-15-/t26-,27+/m1/s1 | InChIKey = KDCCOOGTVSRCHX-YYVBKQGDBH | StdInChI_Ref = | StdInChI = 1S/C33H42N4O6/c1-7-20-19(6)32(42)37-27(20)14-25-18(5)23(10-12-31(40)41)29(35-25)15-28-22(9-11-30(38)39)17(4)24(34-28)13-26-16(3)21(8-2)33(43)36-26/h15,26-27,35H,7-14H2,1-6H3,(H,36,43)(H,37,42)(H,38,39)(H,40,41)/b28-15-/t26-,27+/m1/s1 | StdInChIKey_Ref = | StdInChIKey = KDCCOOGTVSRCHX-YYVBKQGDSA-N | RTECS = | MeSHName = | ChEBI_Ref = | ChEBI = 45097 |Section2={{Chembox Properties | Formula=C33H42N4O6 | MolarMass=590.71 | Appearance= | Density= | MeltingPt= | BoilingPt= | Solubility= |Section3={{Chembox Hazards | MainHazards= | FlashPt= | AutoignitionPt = Phycourobilin is an orange tetrapyrrole involved in photosynthesis in cyanobacteria and red algae. This chromophore is bound to the phycobiliprotein phycoerythrin, the distal component of the light-harvesting system of cyanobacteria and red algae (phycobilisome).
When bound to phycoerythrin, phycourobilin shows an absorption maximum around 495 nm. This chromophore is always a donor chromophore of phycoerythrins, since their acceptor chromophore is always phycoerythrobilin. It can also be linked to the linker polypeptides of the phycobilisome, in which its precise role remains unclear.
Phycourobilin is found in marine phycobilisome containing organisms, allowing them to efficiently absorb blue-green light. In the ubiquitous marine cyanobacteria Synechococcus, the amount of phycourobilin in the phycobilisomes is correlated to the ecological niche the cells inhabit: offshore Synechococcus are quite phycourobililin-rich, while coastal Synechococcus contain very little or no phycourobilin. This represents a remarkable adaptation of the cyanobacterial light-harvesting system, as oceanic waters are relatively richer in blue light than onshore waters.
References
References
- (2018). "The γ33 subunit of R-phycoerythrin from ''Gracilaria chilensis'' has a typical double linked phycourobilin similar to β subunit". PLOS ONE.
::callout[type=info title="Wikipedia Source"] This article was imported from Wikipedia and is available under the Creative Commons Attribution-ShareAlike 4.0 License. Content has been adapted to SurfDoc format. Original contributors can be found on the article history page. ::