2ib5
Structural characterization of a blue chromoprotein and its yellow mutant from the sea anemone cnidopus japonicus
|
OverviewOverview
Green fluorescent protein (GFP) and its relatives (GFP protein family), have been isolated from marine organisms such as jellyfish and corals that, belong to the phylum Cnidaria (stinging aquatic invertebrates). They are, intrinsically fluorescent proteins. In search of new members of the family, of green fluorescent protein family, we identified a non-fluorescent, chromoprotein from the Cnidopus japonicus species of sea anemone that, possesses 45% sequence identity to dsRed (a red fluorescent protein). This, newly identified blue color protein has an absorbance maximum of 610 nm, and is hereafter referred to as cjBlue. Determination of the cjBlue 1.8 A, crystal structure revealed a chromophore comprised of, Gln(63)-Tyr(64)-Gly(65). The ring stacking between Tyr(64) and His(197), stabilized the cjBlue trans chromophore conformation along the, Calpha2-Cbeta2 bond of 5-[(4-hydroxyphenyl)methylene]-imidazolinone, which, closely resembled that of the "Kindling Fluorescent Protein" and Rtms5., Replacement of Tyr(64) with Leu in wild-type cjBlue produced a visible, color change from blue to yellow with a new absorbance maximum of 417 nm., Interestingly, the crystal structure of the yellow mutant Y64L revealed, two His(197) imidazole ring orientations, suggesting a flip-flop, interconversion between the two conformations in solution. We conclude, that the dynamics and structure of the chromophore are both essential for, the optical appearance of these color proteins.
About this StructureAbout this Structure
2IB5 is a Single protein structure of sequence from Cnidopus japonicus with as ligand. Full crystallographic information is available from OCA.
ReferenceReference
Structural characterization of a blue chromoprotein and its yellow mutant from the sea anemone Cnidopus japonicus., Chan MC, Karasawa S, Mizuno H, Bosanac I, Ho D, Prive GG, Miyawaki A, Ikura M, J Biol Chem. 2006 Dec 8;281(49):37813-9. Epub 2006 Oct 6. PMID:17028187
Page seeded by OCA on Tue Jan 29 20:38:05 2008