Biology Reference
In-Depth Information
genes involved in general metabolism, electron transport, virulence and
defence against different stresses.
3.1.1. Structural features of Fur proteins
Although Fur-like proteins have a wide diversity of metal selectivity and bio-
logical functions, they share a similar architecture that serves to better under-
stand the activation and metal discrimination mechanism of this group of
proteins. The first crystal structure for a Fur homologue showed a basic fold-
ing with two well-defined domains: an N-terminal DNA-binding domain
and a C-terminal dimerization domain (
Pohl et al., 2003
). The DNA-binding
domain of Fur from
Pseudomonas aeruginosa
was composed of four helices
followed by a two-stranded antiparallel β-sheet displaying a winged helix-
turn-helix (HTH) motif (
Fig. 4.1
). The dimerization domain of each Fur
monomer consisted of two structural elements that were involved in form-
ing the functional protein dimer, an α/β-domain and a long α-helix covered
by three antiparallel β-strands from the first element. Although this main
folding has been confirmed by X-ray crystallography of other members of
the Fur family of metalloregulators, such as
Helicobacter pylori
Fur (
Dian et al.,
2011
),
Streptomyces coleicolor
Nur (
An et al., 2009
),
Mycobacterium tuberculo-
sis
FurB/Zur (
Lucarelli et al., 2007
) or
Bacillus subtilis
PerR (
Jacquamet
et al., 2009
), there are structural differences that may be responsible for some
exceptions in the regulatory capacity observed in this protein family (
Dian
et al., 2011
;
Hernández, Bes, Fillat, Neira, & Peleato, 2002
).
Figure 4.1
Three-dimensional model of
Pseudomonas aeruginosa
Fur generated by
PISA Server (
Krissinel & Henrick, 2007
) and drawn using PyMOL (
Delano, 2006
). Several
chains of amino acids discussed in the text are shown in darker grey. For colour version
of this igure, the reader is referred to the online version of this topic.
