Extended Data Fig. 3: Heliorhodopsin membrane topology.
From: A distinct abundant group of microbial rhodopsins discovered using functional metagenomics
a, Predictions of membrane topology for type-1 rhodopsins, type-2 rhodopsins and heliorhodopsin. Upper panel, suggested schematic topologies for type-1 rhodopsins, type-2 rhodopsins and heliorhodopsins. Positively charged amino acids are labelled. N, amino-terminal tail, C, carboxy-terminal tail. Middle panel, membrane topology predictions by TMHMM35, Phobius36, Philius37 and SPOCTOPUS38. Lower panel, the rhodopsin sequences used for membrane topology predictions. b, Arrangement of heliorhodopsin 48C12 protein across the E. coli membrane. The heliorhodopsin–β-lactamase fusion sites resulting in ampicillin resistance (ampr) and ampicillin sensitivity (amps) are indicated. This experiment was repeated twice.
