Dear ccp4bb crowd, Thank you for the wealth of useful replies to my request! I've received over 100 messages with suggestions!
A crude summary of replies is presented below (I've added PDB ID to most of these). Overwhelmingly, the preferences tended towards iron-loaded proteins (red or brown) and copper-loaded proteins (blue) as well as proteins carrying specialized ligands used to harvest light. An equally abundant group of suggestions concerned enzymes loaded with brightly colored organic cofactors (PLP, flavonoids, etc.) The most popular suggestion was cytochrome(s) closely followed by redox copper proteins. The most memorable (at least to me!) suggestion was ranasmurfin - a blue protein from floating foam nests made by tree frogs. It's good to know that sense of humor is alive and well in the sciences. The smallest brightly colored protein that I could identify so far seems to be rubredoxin (52aa) which also happens to be one of the top 1% highest-resolution protein structures in the PDB (at least by my count). The list below has been pruned for obvious replicates. Again, thank you - this has been extremely useful! Artem B. stearothermophilus Mn Superoxide Dismutase - nice purple brown color ThyX (Flavin Dependent Thymidyalte Synthase, FDTS) is yellow due to bound FAD azurin, plastocyanin, CueO (1kv7), ascorbate oxidase, ceruloplasmin HemS from Y.enterocolitica (2j0p, 2j0r) and Shp from S.pyogenes (2q7a) (whole culture turns reddish) Quinone reductase Nqo2 - flavoenzyme, bright yellow (3fw1) APS reductase (FAD FeS) - yellow/brown (2goy), rubredoxin (FeS) - brown (2v3b), Sulfite reductase (Siroheme, FeS) - green (1aop), cytochromes c - red. D. vulgaris flavodoxin - purple (reduced) yellow (oxidized) (1bu5) rubredoxin - dark red Crustacyanin - blue & red (1s44) Ranasmurfin - smurfin' blue (2vh3) Peptide deformylase - red (3e3u), diaminopimelate decarboxylase (2qgh), alanine racemase (2vd8) - yellow E.coli cytochrome b562 - red (256b), Insect bilin-binding protein (1bbp) - blue, gelatinase-associated lipocalin - red (with siderophore from E. coli, 1L6M) MICAL from drosophila (2bry) - yellow Auracyanin (2aan, 1ov8), stellacyanin (1jer), umecyanin (1x9r), plastocyanin (1ag6), cucumber basic protein (2cbp) - blue Phycocyanin (3brp), crystacyanin, rusticyanin (1a3z), insecticyanin (lipocalin, binds biliverdin 1z24) - blue, carotenoid-binding proteins - red, light-harvesting proteins - red, green, or blue Glucose oxidase - yellow (1cf3) dihydroorotate dehydrogenase - yellow (1f76) catalase (1tgu) - brown phycobiliproteins (phycocyanin, allophycocyanin, phycoerythrin)- red or blue or cyan cytochrome c - red/brown (1GWS) light harvesting complexes from purple bacteria - purple (2fkW) myoglobin, haemoglobin - brown/red, hemocyanin (1hc1) - blue FMO protein (3eoj) - green Peridinin-chlorophyll protein (1ppr) - green Methylamine dehydrogenase (2gc7) - yellow 'old yellow' - yellow (1oya) Bacterioferritin (1bfr) or ferritin - brown LHC-II from plants - green Indoleamine 2,3-dioxygenase (2d0t) - red Cytochrome b5 (1cyo) - red Cytochrome bc1 complex () - red/orange Phosphotriesterase-like protein from D. radiodurans (3gtf) - pink or purple Nitrosocyanin (1iby) - red
