Chemistry Reference
In-Depth Information
barrel,
which is occluded by an independently folded mixed
ab
globular 'cork' domain of around 160 amino acid
residues. This is illustrated for a vitamin B12 receptor and the ferric siderophore receptors for citrate, enterobactin,
ferrichrome, pyochelin, and pyoverdin from E. coli and P. aeruginosa in
Fig. 7.6
.
The ferric siderophore sits on top
of the 'cork' domain, as can be seen in
Fig. 7.7
for FecA. The binding of the ligand induces a conformational
All outer-membrane transporters (OMTs) involved in iron uptake are made up of a 22-stranded
b
(a)
(b)
(c)
(d)
(e)
(f)
FIGURE 7.6
Outer-membrane siderophore receptors from Escherichia coli and Pseudomonas aeruginosa. Ribbon representations of the
(a) vitamin B
12
(BtuB), (b) E. coli ferric-citrate (FecA), (c) ferric-enterobactin (FepA), (d) ferric-hydroxamate (FhuA), (e) P. aeruginosa
pyochelin (FptA), and (f) P. aeruginosa pyoverdin (FpvA) receptors. The mixed
a
e
b
globular (cork) domain is coloured green while the
22-strand
b
-barrel is coloured blue.
(From
Krewulak & Vogel, 2008
.
Reproduced with permission from Elsevier.)
