PDBsum entry 1jv6

Ion transport

PDB id: 1jv6

Contents

Protein chain

208 a.a. *

Ligands

RET

LI1 ×8

Waters ×34

* Residue conservation analysis

PDB id:

1jv6

Name:

Ion transport

Title:

Bacteriorhodopsin d85s/f219l double mutant at 2.00 angstrom resolution

Structure:

Bacteriorhodopsin. Chain: a. Synonym: br. Engineered: yes. Mutation: yes

Source:

Halobacterium salinarum. Organism_taxid: 2242. Gene: bop. Expressed in: halobacterium salinarum. Expression_system_taxid: 2242.

Resolution:

2.00Å R-factor: 0.222 R-free: 0.240

Authors:

S.Rouhani,J.-P.Cartailler,M.T.Facciotti,P.Walian,R.Needleman, J.K.Lanyi,R.M.Glaeser,H.Luecke

Key ref:

S.Rouhani et al. (2001). Crystal structure of the D85S mutant of bacteriorhodopsin: model of an O-like photocycle intermediate. J Mol Biol, 313, 615-628. PubMed id: 11676543 DOI: 10.1006/jmbi.2001.5066

Date:

28-Aug-01 Release date: 31-Oct-01

Protein chain

P02945  (BACR_HALSA) -  Bacteriorhodopsin from Halobacterium salinarum (strain ATCC 700922 / JCM 11081 / NRC-1)

Seq: 262 a.a.

Struc: 208 a.a.*

* PDB and UniProt seqs differ at 2 residue positions (black crosses)

DOI no: 10.1006/jmbi.2001.5066

J Mol Biol 313:615-628 (2001)

PubMed id: 11676543

Crystal structure of the D85S mutant of bacteriorhodopsin: model of an O-like photocycle intermediate.

S.Rouhani, J.P.Cartailler, M.T.Facciotti, P.Walian, R.Needleman, J.K.Lanyi, R.M.Glaeser, H.Luecke.

ABSTRACT

Crystal structures are reported for the D85S and D85S/F219L mutants of the light-driven proton/hydroxyl-pump bacteriorhodopsin. These mutants crystallize in the orthorhombic C222(1) spacegroup, and provide the first demonstration that monoolein-based cubic lipid phase crystallization can support the growth of well-diffracting crystals in non-hexagonal spacegroups. Both structures exhibit similar and substantial differences relative to wild-type bacteriorhodopsin, suggesting that they represent inherent features resulting from neutralization of the Schiff base counterion Asp85. We argue that these structures provide a model for the last photocycle intermediate (O) of bacteriorhodopsin, in which Asp85 is protonated, the proton release group is deprotonated, and the retinal has reisomerized to all-trans. Unlike for the M and N photointermediates, where structural changes occur mainly on the cytoplasmic side, here the large-scale changes are confined to the extracellular side. As in the M intermediate, the side-chain of Arg82 is in a downward configuration, and in addition, a pi-cloud hydrogen bond forms between Trp189 NE1 and Trp138. On the cytoplasmic side, there is increased hydration near the surface, suggesting how Asp96 might communicate with the bulk during the rise of the O intermediate.

Selected figure(s)

Figure 5.
Figure 5. View of the extracellu- lar side, showing an extensive hydrogen-bonding network of side- chains and water molecules, as well as the alternate conformation of Glu194. Not only is the hydro- gen-bonding network between the Schiff base and the proton release group broken, but Arg82 is now in a downward configuration with hydrogen bonds towards the pro- ton release group similar to what is observed for M intermediates. Somewhat long hydrogen bonds exist from Arg82-NH2 to water 408 (3.44 Å ) and from Arg82-NH1 to water 409 (3.25 Å ).

Figure 7.
Figure 7. View of the cyto- plasmic side, showing Phe42 acting as a barrier between Asp96 and the bulk aqueous phase. This region contains numerous ordered water molecules that form a hydrogen- bonding network and are likely to be involved in the reprotonation of Asp96 during the N ! O tran- sition.

The above figures are reprinted by permission from Elsevier: J Mol Biol (2001, 313, 615-628) copyright 2001.

Figures were selected by an automated process.