 |
PDBsum entry 2b10
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
 |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Oxidoreductase/electron transport
|
PDB id
|
|
|
|
2b10
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
References listed in PDB file
|
|
|
Key reference
|
|
|
Title
|
|
Effects of interface mutations on association modes and electron-Transfer rates between proteins.
|
|
|
Authors
|
|
S.A.Kang,
B.R.Crane.
|
|
|
Ref.
|
|
Proc Natl Acad Sci U S A, 2005,
102,
15465-15470.
[DOI no: ]
|
|
|
PubMed id
|
|
|
|
|
|
Abstract
|
|
|
Although bonding networks determine electron-transfer (ET) rates within
proteins, the mechanism by which structure and dynamics influence ET across
protein interfaces is not well understood. Measurements of photochemically
induced ET and subsequent charge recombination between Zn-porphyrin-substituted
cytochrome c peroxidase and cytochrome c in single crystals correlate reactivity
with defined structures for different association modes of the redox partners.
Structures and ET rates in crystals are consistent with tryptophan oxidation
mediating charge recombination reactions. Conservative mutations at the
interface can drastically affect how the proteins orient and dispose redox
centers. Whereas some configurations are ET inactive, the wild-type complex
exhibits the fastest recombination rate. Other association modes generate ET
rates that do not correlate with predictions based on cofactor separations or
simple bonding pathways. Inhibition of photoinduced ET at <273 K indicates
gating by small-amplitude dynamics, even within the crystal. Thus, different
associations achieve states of similar reactivity, and within those states
conformational fluctuations enable interprotein ET.
|
|
|
|
|
|
|
|
Figure 1.
Fig. 1. Reactions initiated by photoinduced ET between
ZnCcP and Fe(III) yCc.
|
|
Figure 2.
Fig. 2. Complexes of ZnCcP with various Cc mutants have
different association modes. (A) Representative ribbon diagrams
for ZnCcP bound to Cc variants. From left to right: yCc WT,
F82W, and F82S mutants; yCc F82Y and F82I mutants; horse Cc; yCc
K72S/F82Y. (B) Relative positioning and interface structures for
the ZnCcP:F82W yCc (Left) and ZnCcP:yCc F82I (Right) complexes.
Cc (gray ribbons, top) rotates 90° and
translates8Åinthe F82I mutant generating altered heme
orientations (yellow bonds), interprotein contacts (black and
orange side chains), and intervening solvent structure (red
spheres) with CcP (yellow, below) compared with the F82W
complex. (C) Superposition of ZnCcP from the two ZnCcP: F82S yCc
complexes (red and blue) indicate variability in Cc positioning
within the asymmetric unit.
|
|
|
|
|
|
|
|
|
|
