Unknown

Dataset Information

0

Crystal structures of the L1, L2, N, and O states of pharaonis halorhodopsin.


ABSTRACT: Halorhodopsin from Natronomonas pharaonis (pHR) functions as a light-driven halide ion pump. In the presence of halide ions, the photochemical reaction of pHR is described by the scheme: K? L1 ? L2 ? N ? O ? pHR' ? pHR. Here, we report light-induced structural changes of the pHR-bromide complex observed in the C2 crystal. In the L1-to-L2 transition, the bromide ion that initially exists in the extracellular vicinity of retinal moves across the retinal Schiff base. Upon the formation of the N state with a bromide ion bound to the cytoplasmic vicinity of the retinal Schiff base, the cytoplasmic half of helix F moves outward to create a water channel in the cytoplasmic interhelical space, whereas the extracellular half of helix C moves inward. During the transition from N to an N-like reaction state with retinal assuming the 13-cis/15-syn configuration, the translocated bromide ion is released into the cytoplasmic medium. Subsequently, helix F relaxes into its original conformation, generating the O state. Anion uptake from the extracellular side occurs when helix C relaxes into its original conformation. These structural data provide insight into the structural basis of unidirectional anion transport.

SUBMITTER: Kouyama T 

PROVIDER: S-EPMC4457492 | BioStudies | 2015-01-01

REPOSITORIES: biostudies

Similar Datasets

2013-01-01 | S-EPMC3552262 | BioStudies
2000-01-01 | S-EPMC384371 | BioStudies
2016-01-01 | S-EPMC5012209 | BioStudies
2009-01-01 | S-EPMC2665073 | BioStudies
2003-01-01 | S-EPMC1303101 | BioStudies
1000-01-01 | S-EPMC3151825 | BioStudies
2019-01-01 | S-EPMC6624782 | BioStudies
2013-01-01 | S-EPMC4629687 | BioStudies
2019-01-01 | S-EPMC6811361 | BioStudies
1999-01-01 | S-EPMC22183 | BioStudies