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| Names | |
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| IUPAC name 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 | |
| Identifiers | |
3D model (JSmol) | |
| ChEBI | |
| ChemSpider |
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| UNII | |
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| Properties | |
| C33H42N4O6 | |
| Molar mass | 590.71 |
Except where otherwise noted, data are given for materials in theirstandard state (at 25 °C [77 °F], 100 kPa). | |
Phycourobilin is an orangetetrapyrrole involved inphotosynthesis in cyanobacteria and red algae. This chromophore is bound to thephycobiliproteinphycoerythrin, the distal component of the light-harvesting system of cyanobacteria and red algae (phycobilisome).[1]
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 alwaysphycoerythrobilin. 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 cyanobacteriaSynechococcus, the amount of phycourobilin in the phycobilisomes is correlated to the ecological niche the cells inhabit: offshoreSynechococcus are quite phycourobililin-rich, while coastalSynechococcus 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.
