4b9o | pdb_00004b9o

The PR0 Photocycle Intermediate of Photoactive Yellow Protein

spinqualitylabelsall models 4b9o, resolution 1.60Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 4b9o is a 1 chain structure with sequence from Halorhodospira halophila. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Ligands: HC4 Related: 1d7e, 1f98, 1f9i, 1gsv, 1gsw, 1gsx, 1kou, 1nwz, 1odv, 1ot6, 1ot9, 1ota, 1otb, 1otd, 1ote, 1oti, 1s1y, 1s1z, 1s4r, 1s4s, 1t18, 1t19, 1t1a, 1t1b, 1t1c, 1ts0, 1ts6, 1ts7, 1ts8, 1ugu, 1uwn, 1uwp, 1xfn, 1xfq, 2d01, 2d02, 2phy, 2pyp, 2pyr, 3phy, 3pyp, 4bbt, 4bbu, 4bbv Resources: FirstGlance, OCA, RCSB, PDBsum Function [PYP_HALHA] Photoactive blue light protein. Probably functions as a photoreceptor for a negative phototaxis response. Publication Abstract from PubMed To understand how signaling proteins function, it is crucial to know the time-ordered sequence of events that lead to the signaling state. We recently developed on the BioCARS 14-IDB beamline at the Advanced Photon Source the infrastructure required to characterize structural changes in protein crystals with near-atomic spatial resolution and 150-ps time resolution, and have used this capability to track the reversible photocycle of photoactive yellow protein (PYP) following trans-to-cis photoisomerization of its p-coumaric acid (pCA) chromophore over 10 decades of time. The first of four major intermediates characterized in this study is highly contorted, with the pCA carbonyl rotated nearly 90 degrees out of the plane of the phenolate. A hydrogen bond between the pCA carbonyl and the Cys69 backbone constrains the chromophore in this unusual twisted conformation. Density functional theory calculations confirm that this structure is chemically plausible and corresponds to a strained cis intermediate. This unique structure is short-lived ( approximately 600 ps), has not been observed in prior cryocrystallography experiments, and is the progenitor of intermediates characterized in previous nanosecond time-resolved Laue crystallography studies. The structural transitions unveiled during the PYP photocycle include trans/cis isomerization, the breaking and making of hydrogen bonds, formation/relaxation of strain, and gated water penetration into the interior of the protein. This mechanistically detailed, near-atomic resolution description of the complete PYP photocycle provides a framework for understanding signal transduction in proteins, and for assessing and validating theoretical/computational approaches in protein biophysics. Watching a signaling protein function in real time via 100-ps time-resolved Laue crystallography.,Schotte F, Cho HS, Kaila VR, Kamikubo H, Dashdorj N, Henry ER, Graber TJ, Henning R, Wulff M, Hummer G, Kataoka M, Anfinrud PA Proc Natl Acad Sci U S A. 2012 Nov 20;109(47):19256-61. doi:, 10.1073/pnas.1210938109. Epub 2012 Nov 6. PMID:23132943 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

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