 |
PDBsum entry 3cge
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
 |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Oxidoreductase
|
PDB id
|
|
|
|
3cge
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
References listed in PDB file
|
|
|
Key reference
|
|
|
Title
|
|
Pyridine nucleotide complexes with bacillus anthracis coenzyme a-Disulfide reductase: a structural analysis of dual NAD(p)h specificity.
|
|
|
Authors
|
|
J.R.Wallen,
C.Paige,
T.C.Mallett,
P.A.Karplus,
A.Claiborne.
|
|
|
Ref.
|
|
Biochemistry, 2008,
47,
5182-5193.
|
|
|
PubMed id
|
|
|
|
|
|
Abstract
|
|
|
We have recently reported that CoASH is the major low-molecular weight thiol in
Bacillus anthracis [Nicely, N. I. , Parsonage, D., Paige, C., Newton, G. L.,
Fahey, R. C., Leonardi, R., Jackowski, S., Mallett, T. C., and Claiborne, A.
(2007) Biochemistry 46, 3234-3245], and we have now characterized the kinetic
and redox properties of the B. anthracis coenzyme A-disulfide reductase (CoADR,
BACoADR) and determined the crystal structure at 2.30 A resolution. While the
Staphylococcus aureus and Borrelia burgdorferi CoADRs exhibit strong preferences
for NADPH and NADH, respectively, B. anthracis CoADR can use either pyridine
nucleotide equally well. Sequence elements within the respective NAD(P)H-binding
motifs correctly reflect the preferences for S. aureus and Bo. burgdorferi
CoADRs, but leave questions as to how BACoADR can interact with both pyridine
nucleotides. The structures of the NADH and NADPH complexes at ca. 2.3 A
resolution reveal that a loop consisting of residues Glu180-Thr187 becomes
ordered and changes conformation on NAD(P)H binding. NADH and NADPH interact
with nearly identical conformations of this loop; the latter interaction,
however, involves a novel binding mode in which the 2'-phosphate of NADPH points
out toward solvent. In addition, the NAD(P)H-reduced BACoADR structures provide
the first view of the reduced form (Cys42-SH/CoASH) of the Cys42-SSCoA redox
center. The Cys42-SH side chain adopts a new conformation in which the conserved
Tyr367'-OH and Tyr425'-OH interact with the nascent thiol(ate) on the flavin
si-face. Kinetic data with Y367F, Y425F, and Y367,425F BACoADR mutants indicate
that Tyr425' is the primary proton donor in catalysis, with Tyr367' functioning
as a cryptic alternate donor in the absence of Tyr425'.
|
|
|
|
|
|
|
