 |
PDBsum entry 1kut
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
 |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Structural genomics, ligase
|
PDB id
|
|
|
|
1kut
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
 |
Contents |
 |
|
|
|
|
|
|
|
|
|
|
* Residue conservation analysis
|
|
|
|
|
References listed in PDB file
|
|
|
Key reference
|
|
|
Title
|
|
Structure of saicar synthase from thermotoga maritima at 2.2 angstroms reveals an unusual covalent dimer.
|
|
|
Authors
|
|
R.Zhang,
T.Skarina,
E.Evdokimova,
A.Edwards,
A.Savchenko,
R.Laskowski,
M.E.Cuff,
A.Joachimiak.
|
|
|
Ref.
|
|
Acta Crystallograph Sect F Struct Biol Cryst Commun, 2006,
62,
335-339.
[DOI no: ]
|
|
|
PubMed id
|
|
|
|
|
|
|
|
|
Abstract
|
|
|
As a part of a structural genomics program, the 2.2 angstroms resolution crystal
structure of the PurC gene product from Thermotoga maritima has been solved.
This 26.2 kDa protein belongs to the
phophoribosylaminoimidazole-succinocarboxamide or SAICAR synthase family of
enzymes, the members of which are involved in de novo purine biosynthesis.
SAICAR synthase can be divided into three subdomains: two alpha+beta regions
exhibiting structural homology with ATP-binding proteins and a carboxy-terminal
subdomain of two alpha-helices. The asymmetric unit contains two copies of the
protein which are covalently linked by a disulfide bond between Cys126(A) and
Cys126(B). This 230-amino-acid protein exhibits high structural homology with
SAICAR synthase from baker's yeast. The protein structure is described and
compared with that of the ATP-SAICAR synthase complex from yeast.
|
|
|
|
|
|
|
|
Figure 1.
Figure 1 Ribbon schematic of the T. maritima SAICAR synthase
monomer. The peptide chain is colored blue to red from the N- to
the C-terminus. Conserved residue Glu172 is labeled E172; Cys126
is labeled C126 and is cross-linked to its counterpart in the
second molecule of the asymmetric unit. All ribbon figures were
generated using PyMOL (DeLano, 2002[DeLano, W. L. (2002). The
PyMOL Molecular Graphics System. http://www.pymol.org .]).
|
|
Figure 3.
Figure 3 Dimeric SAICAR synthase. The covalent dimer is
pictured here in stereo with one peptide chain in red and the
other in blue. The amino-termini are labeled N and the
carboxy-termini are labeled C. The disulfide bridge is located
across a (noncrystallographic) twofold axis and is shown as
yellow sticks.
|
|
|
|
|
|
The above figures are
reprinted
from an Open Access publication published by the IUCr:
Acta Crystallograph Sect F Struct Biol Cryst Commun
(2006,
62,
335-339)
copyright 2006.
|
|
|
|
|
|
|
