1t18

Publication Abstract from PubMed

In the bacterial photoreceptor photoactive yellow protein (PYP), absorption of blue light by its chromophore leads to a conformational change in the protein associated with differential signaling activity, as it executes a reversible photocycle. Time-resolved Laue crystallography allows structural snapshots (as short as 150 ps) of high crystallographic resolution (approximately 1.6 A) to be taken of a protein as it functions. Here, we analyze by singular value decomposition a comprehensive time-resolved crystallographic data set of the E46Q mutant of PYP throughout the photocycle spanning 10 ns-100 ms. We identify and refine the structures of five distinct intermediates and provide a plausible chemical kinetic mechanism for their inter conversion. A clear structural progression is visible in these intermediates, in which a signal generated at the chromophore propagates through a distinct structural pathway of conserved residues and results in structural changes near the N terminus, over 20 A distant from the chromophore.

A structural pathway for signaling in the E46Q mutant of photoactive yellow protein.,Rajagopal S, Anderson S, Srajer V, Schmidt M, Pahl R, Moffat K Structure. 2005 Jan;13(1):55-63. PMID:15642261^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.