1otd

STRONG HYDROGEN BONDS IN PHOTOACTIVE YELLOW PROTEIN AND THEIR ROLE IN ITS PHOTOCYCLE

spinqualitylabelsall models 1otd, resolution 1.25Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 1otd is a 2 chain structure with sequence from Halorhodospira halophila. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 1.25Å Ligands: HC4 Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function PYP_HALHA Photoactive blue light protein. Probably functions as a photoreceptor for a negative phototaxis response. Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMed Eight high-resolution crystal structures of the ground state of photoactive yellow protein (PYP) solved under a variety of conditions reveal that its chromophore is stabilized by two unusually short hydrogen bonds. Both Tyr42 Oeta and Glu46 Oepsilon are separated from the chromophore phenolate oxygen by less than the sum of their atomic van der Waals radii, 2.6 angstroms. This is characteristic of strong hydrogen bonding, in which hydrogen bonds acquire significant covalent character. The hydrogen bond from the protonated Glu46 to the negatively charged phenolate oxygen is 2.58 +/- 0.01 angstroms in length, while that from Tyr42 is considerably shorter, 2.49 +/- 0.01 angstroms. The E46Q mutant was solved to 0.95 angstroms resolution; the isosteric mutation increased the length of the hydrogen bond from Glx46 to the chromophore by 0.29 +/- 0.01 angstroms to that of an average hydrogen bond, 2.88 +/- 0.01 angstroms. The very short hydrogen bond from Tyr42 explains why mutating this residue has such a severe effect on the ground-state structure and PYP photocycle. The effect of isosteric mutations on the photocycle can be largely explained by the alterations to the length and strength of these hydrogen bonds. Short hydrogen bonds in photoactive yellow protein.,Anderson S, Crosson S, Moffat K Acta Crystallogr D Biol Crystallogr. 2004 Jun;60(Pt 6):1008-16. Epub 2004, May 21. PMID:15159559 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

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