Phylogenetic tree inferred using the Maximum likelihood method of 21 amino acid sequences of <i>Exiguobacterium</i> spp. closely related with E17R.

<p>The percentage of replicate trees in which the associated taxa clustered together in the bootstrap test (1,000 replicates) are shown next to the branches. The tree is drawn to scale, with branch lengths in the same units as those of the evolutionary distances used to infer the phylogenetic tree.</p

Electrometric record of E17R (in 20 mM Hepes, pH 7.4) with the BLM system.

<p>A. Transient currents and B. after the addition of the protonophore FCCP. Black bars indicate illumination with a 75 W XBO long-pass filtered at >495 nm. The grey bar shows the additional excitation of the M-state (>380 nm).</p

Multiple protein alignment of PR from <i>Exiguobacterium</i> sp. S17 (E17R), green-light absorbing proteorhodopsin from <i>Exiguobacterium sibiricum</i> (ESR) and blue-light absorbing proteorhodopsin from the uncultured gamma-proteobacterium “Hot 75m4” (BPR).

<p>Residues shared between all the protein variants are marked with asterisks. Single amino acid residue at position 106 (BPR numbering) that functions as a spectral tuning switch and accounts for most of the spectral difference between the two pigment families is highlighted in light grey. Primary proton acceptor and donor are highlighted in dark grey (D86) and with a frame (K97), respectively. The Schiff base (K232 for ESR, K226 for E17R) is indicated by a diamond. Residues differing between both green-PRs are indicated with arrows. The seven transmembrane α-helices are indicated with blue bubbles.</p

Absorption spectrum of E17R in 20 mM Hepes, 100 mM NaCl, 0.03% DDM.

<p>The inset shows the difference spectrum after bleaching with hydroxylamine. The extinction coefficient was calculated using the absorbance of the oxime product ΔA(oxime) in comparison to the bleached rhodopsin absorbance ΔA(Rh) as reference.</p

Transient absorbance changes of E17R.

<p>A. The kinetics of the absorbance changes are shown for selected wavelengths (399 nm, 517 nm and 598 nm). B. The decay-associated spectra are depicted as obtained from the global fit. The corresponding time constants are given in the figure.</p