3umd

Structure of pB intermediate of Photoactive yellow protein (PYP) at pH 4.

spinqualitylabelsall models 3umd, resolution 1.80Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 3umd 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: 3ume Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function [PYP_HALHA] Photoactive blue light protein. Probably functions as a photoreceptor for a negative phototaxis response. Publication Abstract from PubMed Visualizing the three-dimensional structures of a protein during its biological activity is key to understanding its mechanism. In general, protein structure and function are pH-dependent. Changing the pH provides new insights into the mechanisms that are involved in protein activity. Photoactive yellow protein (PYP) is a signaling protein that serves as an ideal model for time-dependent studies on light-activated proteins. Its photocycle is studied extensively under different pH conditions. However, the structures of the intermediates remain unknown until time-resolved crystallography is employed. With the newest beamline developments, a comprehensive time series of Laue data can now be collected from a single protein crystal. This allows us to vary the pH. Here we present the first structure, to our knowledge, of a short-lived protein-inhibitor complex formed in the pB state of the PYP photocycle at pH 4. A water molecule that is transiently stabilized in the chromophore active site prevents the relaxation of the chromophore back to the trans configuration. As a result, the dark-state recovery is slowed down dramatically. At pH 9, PYP stops cycling through the pB state altogether. The electrostatic environment in the chromophore-binding site is the likely reason for this altered kinetics at different pH values. pH dependence of the photoactive yellow protein photocycle investigated by time-resolved crystallography.,Tripathi S, Srajer V, Purwar N, Henning R, Schmidt M Biophys J. 2012 Jan 18;102(2):325-32. PMID:22339869 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

Proteopedia Page Contributors and Editors (what is this?)

OCA