Transcript Supplementary Figures - PowerPoint (4.4 MB )

Figure S1 Amino acid sequence alignment of pilin domain proteins (GSU1496
(PilA) and GSU1776 (OxpG)) from G. sulfurreducens and pilins and pseudopilins
from other bacteria. Amino acid sequence alignments were first generated using
the Clustal X (1.8) program and manually optimized using the SeAl v. 2.0a11
Carbon program (University of Oxford). The alignment contains the conserved
amino-terminal domain of pilins and pseudopilins and was used to infer the
phylogenetic tree shown in Fig. 1c. Different amino acid residues were assigned
to one of a number of groups (by chemical similarity) and each group was
assigned a colour.
30
FeOOH
+ NTA
+AQDS
25
Fe(II) (mM)
20
15
10
5
0
wild-type
PilA- mutant
Figure S2 Restoration of Fe(III) oxide (FeOOH) reduction by the PilA- mutant
after media supplementation with 4 mM NTA, an Fe(III) chelator, or 0.1 mM
AQDS, an electron shuttle that alleviates the need for establishing contact with
the insoluble Fe(III) oxides. The levels of soluble Fe(II), produced as a result of
the reduction and growth on Fe(III) oxides, were measured after 3 weeks of
incubation with the insoluble electron acceptor.
b
a
0.1 µm
0.1 µm
c
10 nm
Figure S3 TEM to negatively stained wild-type pili. (a-b) G. sulfurreducens
cells expressing pili after 48h of incubation at 250C in medium with fumarate.
(c) Pili filaments that have been mechanically sheared off the outer surface of
the wild-type strain of G. sulfurreducens. The wild-type pili preparations were
analyzed by conducting-probe AFM (Fig. 4) in order to study the
electroconductive properties of G. sulfurreducens pili.
a
b
20 nm
1 nA
100 nm
c
100 mV
Figure S4 CP-AFM analyses to Shewanella oneidensis MR-1 pili. (a) Height
image of a pilus filament. (b) Current map obtained while applying a sweeping
voltage (c) showing no detectable conductivity across the pilus filament.
a
b
15 nm
1 nA
100 nm
c
200 mV
Figure S5 CP-AFM analyses to Pseudomonas aeruginosa strain K pili. (a)
Height image of several pilus filaments. (b) Current map obtained while
applying a sweeping voltage (c) showing no detectable conductivity across the
pilus filament.