Definition
Bacteriorhodopsin is a membrane protein that captures radiation energy which is used to create a proton gradient. It can be found mainly in Haloarchea. Bacteriorhodopsin is a membrane protein usually found in two-dimensional crystalline patches known as purple membrane. The repeating element of the hexagonal lattice is composed of three identical protein chains, each rotated by 120° relative to the others. Each chain has seven transmembrane alpha helices and contains one molecule of retinal buried deep within. It is the retinal molecule that changes its conformation when absorbing a photon, resulting in a conformational change of the bacteriorhodopsin promoting the proton pumping action. It can be considered the simplest photosynthetic system known. All other phototrophic systems (bacteria, algae, chloroplasts) use chlorophylls instead of bacteriorhodopsin to generate proton gradients.
Access this chapter
Tax calculation will be finalised at checkout
Purchases are for personal use only
Author information
Authors and Affiliations
Corresponding author
Editor information
Editors and Affiliations
Rights and permissions
Copyright information
© 2015 Springer-Verlag Berlin Heidelberg
About this entry
Cite this entry
Amils, R. (2015). Bacterirhodopsin. In: Gargaud, M., et al. Encyclopedia of Astrobiology. Springer, Berlin, Heidelberg. https://doi.org/10.1007/978-3-662-44185-5_5184
Download citation
DOI: https://doi.org/10.1007/978-3-662-44185-5_5184
Published:
Publisher Name: Springer, Berlin, Heidelberg
Print ISBN: 978-3-662-44184-8
Online ISBN: 978-3-662-44185-5
eBook Packages: Physics and AstronomyReference Module Physical and Materials ScienceReference Module Chemistry, Materials and Physics