4HYJ

Crystal structure of Exiguobacterium sibiricum rhodopsin

Summary for 4HYJ

• Entry DOI: 10.2210/pdb4hyj/pdb
• Descriptor: Rhodopsin, RETINAL, EICOSANE, ... (4 entities in total)
• Functional Keywords: seven-helical transmembrane protein, proton pump, membrane, proton transport
• Biological source: Exiguobacterium sibiricum
• Total number of polymer chains: 2
• Total formula weight: 66308.79

Authors

Gushchin, I.,Chervakov, P.,Kuzmichev, P.,Popov, A.,Round, E.,Borshchevskiy, V.,Dolgikh, D.,Kirpichnikov, M.,Petrovskaya, L.,Chupin, V.,Arseniev, A.,Gordeliy, V. (deposition date: 2012-11-13, release date: 2013-07-17, Last modification date: 2024-10-09)

Primary citation

Gushchin, I.,Chervakov, P.,Kuzmichev, P.,Popov, A.N.,Round, E.,Borshchevskiy, V.,Ishchenko, A.,Petrovskaya, L.,Chupin, V.,Dolgikh, D.A.,Arseniev, A.A.,Kirpichnikov, M.,Gordeliy, V.
Structural insights into the proton pumping by unusual proteorhodopsin from nonmarine bacteria.
Proc.Natl.Acad.Sci.USA, 110:12631-12636, 2013

PubMed Abstract: Light-driven proton pumps are present in many organisms. Here, we present a high-resolution structure of a proteorhodopsin from a permafrost bacterium, Exiguobacterium sibiricum rhodopsin (ESR). Contrary to the proton pumps of known structure, ESR possesses three unique features. First, ESR's proton donor is a lysine side chain that is situated very close to the bulk solvent. Second, the α-helical structure in the middle of the helix F is replaced by 3(10)- and π-helix-like elements that are stabilized by the Trp-154 and Asn-224 side chains. This feature is characteristic for the proteorhodopsin family of proteins. Third, the proton release region is connected to the bulk solvent by a chain of water molecules already in the ground state. Despite these peculiarities, the positions of water molecule and amino acid side chains in the immediate Schiff base vicinity are very well conserved. These features make ESR a very unusual proton pump. The presented structure sheds light on the large family of proteorhodopsins, for which structural information was not available previously.

PubMed: 23872846
DOI: 10.1073/pnas.1221629110

Experimental method

X-RAY DIFFRACTION (2.3 Å)