Evidence map›Paper›PMID 22735541›Full record

ArticleBiophysical journal2012

Homotrimer formation and dissociation of pharaonis halorhodopsin in detergent system.

Takashi Tsukamoto, Takanori Sasaki, Kazuhiro J Fujimoto, Takashi Kikukawa, Masakatsu Kamiya, Tomoyasu Aizawa, Keiichi Kawano, Naoki Kamo, Makoto Demura

Abstract read
In one paragraph

Article in Biophysical journal, 2012. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 3 papers.

0numbers the graph read from it
0cells of the map it votes in
3citing papers in PubMed
–field-weighted citation impact
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

3 citing papers in PubMed.

  1. Article
  2. Article
  3. Presence of a Haloarchaeal Halorhodopsin-Like ClMicrobes and environments · 2018
    Article
4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

9 authors.

Takashi TsukamotoFaculty of Advanced Life Science, Hokkaido University, Sapporo, Japan.
Takanori Sasaki
Kazuhiro J Fujimoto
Takashi Kikukawa
Masakatsu Kamiya
Tomoyasu Aizawa
Keiichi Kawano
Naoki Kamo
Makoto Demura

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

Halorhodopsin from NpHR is a light-driven Cl(-) pump that forms a trimeric NpHR-bacterioruberin complex in the native membrane. In the case of NpHR expressed in Escherichia coli cell, NpHR forms a robust homotrimer in a detergent DDM solution. To identify the important residue for the homotrimer formation, we carried out mutation experiments on the aromatic amino acids expected to be located at the molecular interface. The results revealed that Phe(150) was essential to form and stabilize the NpHR trimer in the DDM solution. Further analyses for examining the structural significance of Phe(150) showed the dissociation of the trimer in F150A (dimer) and F150W (monomer) mutants. Only the F150Y mutant exhibited dissociation into monomers in an ionic strength-dependent manner. These results indicated that spatial positions and interactions between F150-aromatic side chains were crucial to homotrimer stabilization. This finding was supported by QM calculations. In a functional respect, differences in the reaction property in the ground and photoexcited states were revealed. The analysis of photointermediates revealed a decrease in the accumulation of O, which is important for Cl(-) release, and the acceleration of the decay rate in L1 and L2, which are involved in Cl(-) transfer inside the molecule, in the trimer-dissociated mutants. Interestingly, the affinity of them to Cl(-) in the photoexcited state increased rather than the trimer, whereas that in the ground state was almost the same without relation to the oligomeric state. It was also observed that the efficient recovery of the photocycle to the ground state was inhibited in the mutants. In addition, a branched pathway that was not included in Cl(-) transportation was predicted. These results suggest that the trimer assembly may contribute to the regulation of the dynamics in the excited state of NpHR.

Indexed as

HalobacteriaceaeAbsorptionAmino Acid SequenceChloridesDetergentsHalorhodopsinsModels, MolecularMolecular Sequence DataMutationPhotolysisProtein MultimerizationProtein StabilityProtein Structure, QuaternarySolutionsStructure-Activity RelationshipChloridesDetergentsHalorhodopsinsSolutions

Identifiers

PMID22735541
PMCPMC3379016

What OpenQuestion holds

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Read underepoch 390

Registered trials

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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.