The bacterial opsins are retinal-binding proteins that provide light- dependent ion transport and sensory functions to a family of halophilic bacteria [2,3]. They are integral membrane proteins believed to contain seven transmembrane (TM) domains, th ...
The bacterial opsins are retinal-binding proteins that provide light- dependent ion transport and sensory functions to a family of halophilic bacteria [2,3]. They are integral membrane proteins believed to contain seven transmembrane (TM) domains, the last of which contains the attachment point for retinal (a conserved lysine). This family also includes distantly related proteins that do not contain the retinal binding lysine and so cannot function as opsins. Some fungal examples are: Swiss:O74870, Swiss:P25619, Swiss:P38079, Swiss:Q12117.
Archaebacterial photoreceptors mediate phototaxis by regulating cell motility through two-component signaling cascades like those found in chemotaxis signaling chains of enteric bacteria. The photoreceptor sensory rhodopsin II from N. pharaonis (NpSR ...
Archaebacterial photoreceptors mediate phototaxis by regulating cell motility through two-component signaling cascades like those found in chemotaxis signaling chains of enteric bacteria. The photoreceptor sensory rhodopsin II from N. pharaonis (NpSRII) in complex with its cognate transducer NpHtrII serves as a system for transmembrane signal transfer. This entry is for the transmembrane domain of the transducer HtrII. Studies suggest that conformation changes of the NpSRII/NpHtrII complex may be crucial for the mechanism of signal propagation spanning the membrane domain and feeding into the HAMP domain [1]. Furthermore, HtrII in H. salinarum not only transmits the signal from the photoreceptor SRII but also operates as a chemoreceptor [2].