BBa_M11051 1 BBa_M11051 Captures light energy and uses it to move protons across the membrane out of the cell. 2009-04-17T11:00:00Z 2015-05-08T01:13:52Z Halobacterium sp.NRC-1 Bacteriorhodopsin is a protein used by archaea, most notably halobacteria. It acts as a proton pump, i.e. it captures light energy and uses it to move protons across the membrane out of the cell. The resulting proton gradient is subsequently converted into chemical energy. Bacteriorhodopsin is an integral membrane protein usually found in two-dimensional crystalline patches known as "purple membrane", which can occupy up to nearly 50% of the surface area of the archaeal cell. The repeating element of the hexagonal lattice is composed of three identical protein chains, each rotated by 120 degrees relative to the others. Each chain has seven transmembrane alpha helices and contains one molecule of retinal buried deep within, the typical structure for retinylidene proteins. It is the retinal molecule that changes its conformation when absorbing a photon, resulting in a conformational change of the surrounding protein and the proton pumping action. It is covalently linked to Lys216 in the chromophore by Schiff base action. After photoisomerization of the retinal molecule, Asp85 becomes a proton acceptor of the donor proton from the retinal molecule. This releases a proton from a "holding site" into the extracellular side (EC) of the membrane. Reprotonation of the retinal molecule by Asp96 restores its original isomerized form. This results in a second proton being released to the EC side. Asp85 releases its proton into the "holding site" where a new cycle may begin. The bacteriorhodopsin molecule is purple and is most efficient at absorbing green light (wavelength 500-650 nm, with the absorption maximum at 568 nm). false false _302_ 0 4564 302 Not in stock false none false Brad Tuft annotation2002481 1 Start range2002481 1 1 3 annotation2002482 1 Stop range2002482 1 787 789 BBa_M11051_sequence 1 atgttggagttattgccaacagcagtggagggggtatcgcaggcccagatcaccggacgtccggagtggatctggctagcgctcggtacggcgctaatgggactcgggacgctctatttcctcgtgaaagggatgggcgtctcggacccagatgcaaagaaattctacgccatcacgacgctcgtcccagccatcgcgttcacgatgtacctctcgatgctgctggggtatggcctcacaatggtaccgttcggtggggagcagaaccccatctactgggcgcggtacgctgactggctgttcaccacgccgctgttgttgttagacctcgcgttgctcgttgacgcggatcagggaacgatccttgcgctcgtcggtgccgacggcatcatgatcgggaccggcctggtcggcgcactgacgaaggtctactcgtaccgcttcgtgtggtgggcgatcagcaccgcagcgatgctgtacatcctgtacgtgctgttcttcgggttcacctcgaaggccgaaagcatgcgccccgaggtcgcatccacgttcaaagtactgcgtaacgttaccgttgtgttgtggtccgcgtatcccgtcgtgtggctgatcggcagcgaaggtgcgggaatcgtgccgctgaacatcgagacgctgctgttcatggtgcttgacgtgagcgcgaaggtcggcttcgggctcatcctcctgcgcagtcgtgcgatcttcggcgaagccgaagcgccggagccgtccgccggcgacggcgcagccgcgaccagcgactga igem2sbol 1 iGEM to SBOL conversion Conversion of the iGEM parts registry to SBOL2.1 Chris J. Myers James Alastair McLaughlin 2017-03-06T15:00:00.000Z