 |
PDBsum entry 1t1c
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
 |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Photoreceptor
|
PDB id
|
|
|
|
1t1c
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
References listed in PDB file
|
|
|
Key reference
|
|
|
Title
|
|
A structural pathway for signaling in the e46q mutant of photoactive yellow protein.
|
|
|
Authors
|
|
S.Rajagopal,
S.Anderson,
V.Srajer,
M.Schmidt,
R.Pahl,
K.Moffat.
|
|
|
Ref.
|
|
Structure, 2005,
13,
55-63.
[DOI no: ]
|
|
|
PubMed id
|
|
|
|
|
|
Abstract
|
|
|
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.
|
|
|
|
|
|
Figure 5.
Figure 5. The Chemical Kinetic Mechanism of E46Q PYP in the
Crystal
(A) Chemical kinetic mechanism of E46Q PYP in the
crystal, with rate coefficients (s -1) of 3.0 × 10^6 (IE1->IE2),
5.0 × 10^5 (IE2->IL1), 5.0 × 10^3 (IL1->IL2), 3.0 × 10^3
(IL1->G), 50 (IL2->IL3), and 0 (IL3->G).
(B) Predicted
concentrations of IE1 (red), IE2 (magenta), IL1 (blue), IL2
(cyan), IL3 (dashed), and the ground state (black) with the
mechanism in (A).
(C) Predicted concentration profiles for
spectroscopic intermediates pR (IE1 and IE2) shown in red, pB
(IL1 and IL2) shown in blue, and the ground state (IL3 and pG)
shown in black with the mechanism in (A).
|
|
|
|
|
|
The above figure is
reprinted
by permission from Cell Press:
Structure
(2005,
13,
55-63)
copyright 2005.
|
|
|
|
|
|
|
