Table 3 Candidate residues for spectral shifting between paralogous LWS opsin copies e.g., LWS1 vs. LWS2) based on combined evidence
Gene | Site | Location | Positive branch-site selection in Buprestidae (this study) | Branch label (see Fig. X) | LWS1 residue | LWS2 residue | LWS3 residue (EAB males) | Structural significance of substitution (this study) | Positive selection in other organisms at homologous sites (previous studies) | Wavelength shifts in other organisms at homologous sites (previous studies) |
|---|---|---|---|---|---|---|---|---|---|---|
LW | 44 | TM1 | I | I/M | most likely insignificant (I–M) | Lepidoptera: Limenitis spp. LWS I17M (positive selection and blue shifts) [21, 78]; I44M suggested for Lepidoptera [77]; Mammals: Rhodopsin M44T (3 nm blue shift) [76] | ||||
46 | TM1 | Buprestidae LWS1 | LW-E | T | V | gain of polarity | ||||
I | V | most likely insignificant | ||||||||
C | I | gain of polarity and potential for disulfide bonding | ||||||||
91 | TM2 | A | V/S | most likely insignificant (A–V) or gain of polarity (A–S) | Lepidoptera: Limenitis spp. LWS A64S (positive selection and blue shifts) [21, 78]; Vertebrates: SWS P91S (10 nm blue shift) [82] | |||||
93 | TM2 | Acmaeodera diffusa LWS2 | LW-F | P | E | gain of backbone flexibility, increase in size, gain of negative charge (from neutral) | ||||
122 | CBP, TM3 | T/C | C | gain of potential for disulfide bonding (T–C) | Bovine: E122Q (17 nm blue shift) [12]; Vertebrates: SWS I122M (6 nm blue shift) [82] | |||||
123 | TM3 | Coleoptera LWS (some) + Agrilus planipennis LWS3 (male) | LW-H | V | T | I | loss of polarity (T–I) or most likely insignificant (V–I) | |||
Buprestidae LWS1 | LW-E | V/A | T | loss of polarity | ||||||
156 | TM4 | Coleoptera LWS (some) + Agrilus planipennis LWS3 (male) | LW-H | W | R | Q | gain of positive charge from neutral (W–R), gain of polarity (W–Q), loss of positive charge (to polar) and decrease in size (R–Q) | Lepidoptera: Heliconius UVS M171L [28] | ||
Acmaeodera diffusa LWS 1 | LW-G | W | R | loss of positive charge (to neutral) | ||||||
164 | TM4 | S/T | S/T/C/A | most likely insignificant (S/T–S/T) | Lepidoptera: Limenitis spp., LWS S137A (positive selection and blue shifts) [21]; S138A suggested for Lepidoptera [77]; Humans: S180A (red/green pigment variation, 5 nm shift) [73, 81] | |||||
gain of potential for disulfide bonding (S/T–C) | ||||||||||
loss of polarity (S/T–A) | ||||||||||
170 | TM4 | Coleoptera LWS (some) + Agrilus planipennis LWS3 (male) | LW-H | A | A | L | increase in size (A–L) | Lepidoptera: Heliconius UVS M185L [28] | ||
197 | EL | Coleoptera LWS (some) + Agrilus planipennis LWS3 (male) | LW-H | D | D | E | most likely insignificant (D–E) | Lepidoptera: LWS 170 (blue shifts) [78]; Vertebrates: LWS 197 [80] | ||
211 | CBP, TM5 | Buprestidae LWS1 | LW-E | C | V | gain of polarity and disulfide bond potential | Lepidoptera: Heliconius UVS S125T/A [28] | Bovine: Rh1 H211C (5 nm shift) [12]; Vertebrates: SWS S211C (2 nm blue shift) [82] | ||
242a | CL | Acmaeodera diffusa LWS1 | LW-G | Ab | A | no substitutionb | Coleoptera: Photinus UVS A268 [43] | |||
269 | CBP, TM6 | L/A/M | L | increase in size (A–L) | Bovine: LWS A269T (14 nm toward red) [9]; Human: T269A (red/green pigment variation, 15 nm shift) [73, 81] | |||||
most likely insignificant (M–L) | ||||||||||
274 | TM6 | Buprestidae LWS1 + Acmaeodera diffusa LWS2 | LW-C | T/V/L/A | T | loss of polarity (V/L/A–T) | Lepidoptera: LWS 259 [20] | |||
281 | EL | Coleoptera LWS (some) + Agrilus planipennis LWS3 (male) | LW-H | A | A | K | gain of positive charge (from neutral) and increase in size (A–K) | Coleoptera: Photinus LWS T309 [43] | ||