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PDBsum entry 2k3a
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References listed in PDB file
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Key reference
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Title
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Structural elucidation of the cys-His-Glu-Asn proteolytic relay in the secreted chap domain enzyme from the human pathogen staphylococcus saprophyticus.
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Authors
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P.Rossi,
J.M.Aramini,
R.Xiao,
C.X.Chen,
C.Nwosu,
L.A.Owens,
M.Maglaqui,
R.Nair,
M.Fischer,
T.B.Acton,
B.Honig,
B.Rost,
G.T.Montelione.
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Ref.
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Proteins, 2009,
74,
515-519.
[DOI no: ]
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PubMed id
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Abstract
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No abstract given.
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Figure 1.
Figure 1. (A) Stereoview of the ribbon representation of the
lowest energy conformer (lowest CNS energy) from the ensemble of
deposited solution NMR structures of full length SSP0609
(PDB_ID: 2K3A). Only residues 50-155 are shown. The secondary
structural elements are labeled and the triad sidechain residues
(Cys57, His109, Glu126) are highlighted as red sticks. (B)
ConSurf images of SSP0609 for identical size and orientation as
(A) ConSurf analysis was conducted for the entire CHAP protein
domain family, standard ConSurf residue coloring reflecting the
degree of residue conservation over the entire family were used
(color scheme: magenta, highly conserved; cyan, variable). (C)
Electrostatic potential surface diagrams for SSP0609 shown in
the same orientation as (A) and (B).
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Figure 2.
Figure 2. (A) Characterization of His109 and His153 tautomer
state by 2D ^1H-^15N HMQC spectrum of [U-^15N, 5%^13C] SSP0609
at pH 6.5 and 25°C, obtained on an 800 MHz NMR spectrometer.
Acquisition parameters: ^15N carrier at 205 ppm, ^2J(^15N-^1H) =
22Hz, 2 sec relaxation delay, acquisition dimensions 2048
× 200 complex points, sweep widths 20 ppm (^1H) ×
200 ppm (^15N), and 128 transients per t[1] increment. (B) Plots
of histidine H^  1
chemical shift versus pH for U-^13C,^15N S. saprophyticus
SSP0609 at 298 K, obtained by 2D ^1H-^13C HSQC NMR. Red, His109;
green, His153 (surface exposed); blue, C-terminal His tag
(control); pK[a] values for each are indicated in the plot. (C)
Detailed view of SSP0609 active site showing the cysteine
peptidase catalytic triad formed by Cys57, His109, Glu126, and
the additional participating group Asn128. Showing here are the
strongly conserved Gln56, Thr58, and Gly74 in the active site.
Key hydrogen bond distances: Cys57 S^  -His109
N^  1
= 3.3 Å, His109 N^ 2-Glu126
O^ 2
= 3.2 Å, Glu126 O^ 1-Asn128
N^ 2
= 4.1 Å.
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The above figures are
reprinted
by permission from John Wiley & Sons, Inc.:
Proteins
(2009,
74,
515-519)
copyright 2009.
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