 |
PDBsum entry 1ptk
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
 |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Hydrolase(serine proteinase)
|
PDB id
|
|
|
|
1ptk
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
References listed in PDB file
|
|
|
Key reference
|
|
|
Title
|
|
Studies on the inhibitory action of mercury upon proteinase k.
|
|
|
Authors
|
|
A.Müller,
W.Saenger.
|
|
|
Ref.
|
|
J Biol Chem, 1993,
268,
26150-26154.
|
|
|
PubMed id
|
|
|
|
|
Note In the PDB file this reference is
annotated as "TO BE PUBLISHED".
The citation details given above were identified by an automated
search of PubMed on title and author
names, giving a
perfect match.
|
|
|
|
Abstract
|
|
|
In proteinase K, Cys73 is located "below" the imidazole of the active site
His69. In a 2.4-A resolution x-ray crystal structure of the complex formed
between the enzyme and HgAc2, two Hg(II) positions are found: a fully occupied
site, covalently bound to Cys73 (S gamma), which disrupts the catalytic triad
(Asp39-His69-Ser224), and a 2-fold disordered (25 and 35% occupancy),
noncovalent complexation to His72, Cys73, and Thr76 of lower affinity. The
enzyme is inhibited noncompetitively at low concentrations and competitively
above stoichiometric concentrations of Hg(II), but it retains 7% residual
activity. This can be rationalized if the molecule is flexible enough to permit
transient formation of the catalytic triad. Except for the active site, only
minor structural changes are observed upon binding of Hg(II), but the thermal
stability is reduced by 4 degrees C.
|
|
|
Secondary reference #1
|
|
|
Title
|
|
Three-Dimensional structure of proteinase k at 0.15-Nm resolution.
|
|
|
Authors
|
|
C.Betzel,
G.P.Pal,
W.Saenger.
|
|
|
Ref.
|
|
Eur J Biochem, 1988,
178,
155-171.
|
|
|
PubMed id
|
|
|
|
|
|
|
|
|
|
|
|
|
