 |
PDBsum entry 1vzp
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
 |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
DNA repair protein
|
PDB id
|
|
|
|
1vzp
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
References listed in PDB file
|
|
|
Key reference
|
|
|
Title
|
|
Identification of a zinc finger domain in the human neil2 (nei-Like-2) protein.
|
|
|
Authors
|
|
A.Das,
L.Rajagopalan,
V.S.Mathura,
S.J.Rigby,
S.Mitra,
T.K.Hazra.
|
|
|
Ref.
|
|
J Biol Chem, 2004,
279,
47132-47138.
[DOI no: ]
|
|
|
PubMed id
|
|
|
|
|
|
Abstract
|
|
|
The recently identified human NEIL2 (Nei-like-2) protein, a DNA glycosylase/AP
lyase specific for oxidatively damaged bases, shares structural features and
reaction mechanism with the Escherichia coli DNA glycosylases, Nei and Fpg.
Amino acid sequence analysis of NEIL2 suggested it to have a zinc finger-like
Nei/Fpg. However, the Cys-X2-His-X16-Cys-X2-Cys (CHCC) motif present near the C
terminus of NEIL2 is distinct from the zinc finger motifs of Nei/Fpg, which are
of the C4 type. Here we show the presence of an equimolar amount of zinc in
NEIL2 by inductively coupled plasma mass spectrometry. Individual mutations of
Cys-291, His-295, Cys-315, and Cys-318, candidate residues for coordinating
zinc, inactivated the enzyme by abolishing its DNA binding activity. H295A and
C318S mutants were also shown to lack bound zinc, and a significant change in
their secondary structure was revealed by CD spectra analysis. Molecular
modeling revealed Arg-310 of NEIL2 to be a critical residue in its zinc binding
pocket, which is highly conserved throughout the Fpg/Nei family. A R310Q
mutation significantly reduced the activity of NEIL2. We thereby conclude that
the zinc finger motif in NEIL2 is essential for its structural integrity and
enzyme activity.
|
|
|
|
|
|
|
|
Figure 1.
FIG. 1. Putative zinc finger domain of NEIL2. A, amino acid
sequence alignment of NEIL2 with E. coli Nei and Fpg. The C
termini of Nei and Fpg were aligned with the C-terminal sequence
of NEIL2. The position of the helix two-turn helix motif (H2TH)
is indicated, and the coordinating amino acid residues forming
the zinc finger motif were boxed. B, schematic diagram of the C
terminus of NEIL2 bearing the putative zinc finger motif.
|
|
Figure 6.
FIG. 6. Model of residues 192-319 of NEIL2. A, structural
alignment for NEIL2 and E. coli Fpg (PDB code 1K82 [PDB]
) template generated by 3DPSSM. Identical residues are indicated
by asterisks. Residues that participate in coordination of zinc
ion are highlighted in red and boldface. B, ribbon diagram of a
model of C-terminal region of NEIL2 generated using MOLMOL (49).
The helices (shown in green) form the helix two-turn helix motif
that binds to DNA. CHCC-type  -hairpin zinc finger is
highlighted with coordinating residues Cys-291, His-295,
Cys-315, and Cys-318. C, ribbon diagram of model of C-terminal
region of NEIL2 with DNA generated with MOLMOL. The helices
(shown in blue) form the helix two-turn helix motif that binds
to DNA. CHCC-type -hairpin zinc finger is
highlighted with coordinating residues Cys-291, His-295,
Cys-315, and Cys-318. The zinc ion stabilizes -strands
(shown in green) that is critical to position of the catalytic
residue Arg-310, which is conserved in E. coli Fpg.
|
|
|
|
|
|
The above figures are
reprinted
by permission from the ASBMB:
J Biol Chem
(2004,
279,
47132-47138)
copyright 2004.
|
|
|
|
|
|
|
