page_title: Archaerhodopsin
section_title: Occurrence
hierarchical_section_title: Archaerhodopsin / General features / Occurrence
caption_attribution_description: English: Tertiary structure surface model of Archaerhodopsin.
context_page_description: Archaerhodopsin proteins are a family of retinal-containing photoreceptors found in the archaea genuses Halobacterium and Halorubrum. Like the homologous bacteriorhodopsin protein, archaerhodopsins harvest energy from sunlight to pump H⁺ ions out of the cell, establishing a proton motive force that is used for ATP synthesis. They have some structural similarities to the mammalian GPCR protein rhodopsin, but are not true homologs.
  Archaerhodopsins differ from bR in that the claret membrane, in which they are expressed, includes bacterioruberin, a second chromophore thought to protect against photobleaching. bR also lacks the omega loop structure that has been observed at the N-terminus of the structures of several archaerhodopsins.
  Mutants of Archaerhodopsin-3 are widely used as tools in optogenetics for neuroscience research.
context_section_description: Like other members of the microbial rhodopsin family, archaerhodopsins are expressed in specialised, protein-rich domains of the cell surface membrane, commonly called the claret membrane. In addition to ether lipids, the claret membrane contains bacterioruberin, (a 50-carbon carotenoid pigment) which is thought to protect against photobleaching. Atomic force microscope images of the claret membranes of several archaerhodopsins, show that the proteins are trimeric and are arranged in a hexagonal lattice. Bacterioruberin has also been implicated in oligomerisation and may facilitate protein-protein interactions in the native membrane.
caption: Archaerhodopsin surface model.
exif: {"Image Orientation": "Horizontal (normal)", "Image XResolution": "200", "Image YResolution": "200", "Image ResolutionUnit": "Pixels/Inch", "Image Software": "Adobe Photoshop CS6 (Windows)", "Image DateTime": "2017:10:25 00:41:25", "Image ExifOffset": "164", "Thumbnail Compression": "JPEG (old-style)", "Thumbnail XResolution": "72", "Thumbnail YResolution": "72", "Thumbnail ResolutionUnit": "Pixels/Inch", "Thumbnail JPEGInterchangeFormat": "302", "Thumbnail JPEGInterchangeFormatLength": "12519", "EXIF ColorSpace": "Uncalibrated", "EXIF ExifImageWidth": "1676", "EXIF ExifImageLength": "1648"}