Table 2.
Amino acid sequence alignment of the C‐helix in various microbial rhodopsins
| Rhodopsin type | Amino acid residue number in BR, PR, and NaR | |||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| BR | 82 | 83 | 84 | 85 | 86 | 87 | 88 | 89 | 90 | 91 | 92 | 93 | 94 | 95 | 96 | |
| PR | 94 | 95 | 96 | 97 | 98 | 99 | 100 | 101 | 102 | 103 | 104 | 105 | 106 | 107 | 108 | |
| NaR | 109 | 110 | 111 | 112 | 113 | 114 | 115 | 116 | 117 | 118 | 119 | 120 | 121 | 122 | 123 | |
| BR | R | Y | A | D | W | L | F | T | T | P | L | L | L | L | D | |
| PR | R | Y | I | D | W | L | L | T | V | P | L | L | I | C | E | |
| NaRa | R | Y | L | N | W | L | I | D | V | P | M | L | L | F | Q | |
| ClRb | R | Y | V | N | W | M | A | T | I | P | C | L | L | L | Q | |
| XR | R | Y | V | D | W | L | L | T | V | P | L | L | T | V | E | |
| ActR | R | Y | V | D | W | L | L | T | V | P | L | L | T | V | E | |
| HR | R | Y | L | T | W | A | F | S | T | P | F | I | L | L | A | |
| SRI | R | Y | V | D | W | V | V | T | T | P | L | L | V | G | F | |
| SRII | R | Y | I | D | W | L | V | T | T | P | L | I | V | L | Y | |
| PRc | R | Y | V | D | W | V or I | L | T | V | P | L | M | C | V | E | |
| NaRc | R | Y | L | N | W | L | I or T | D | V | P | M | L | L | F | Q | |
| ClRc | R | Y | V | N | W | M | A | T | I | P | C | L | L | V | Q | |
The bold indicates active site residues of microbial rhodopsins. This analysis was conducted as described by Inoue et al. (2013). PR, proteorhodopsin; BR, Bacteriorhodopsin; NaR, Sodium ion rhodopsin; ClR, chloride ion rhodopsin; XR, Xanthorhodopsin; ActR, Actinorhodopsin; SRI, sensory rhodopsin I; SRII, sensory rhodopsin II.
a
K. eikastus NBRC 100814T and N. dokdonensis DSW‐6T.
b
N. marinus S1‐08T.
c
Indicates the rhodopsins discovered during this study.