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Volume 10, Issue 8 (Suppl)

J Proteomics Bioinform, an open access journal

ISSN: 0974-276X

Structural Biology 2017

September 18-20, 2017

International Conference on

Structural Biology

September 18-20, 2017 Zurich, Switzerland

Structure and function of a chloride pump rhodopsin from marine bacteria

Hyun-Soo Cho

Yonsei University, South Korea

ecently, light-driven sodium pump rhodopsin (NaR/KR2/NDQ rhodopsin) and chloride pump rhodopsin (ClR/NTQ

rhodopsin) from marine flavobacteria were identified by metagenomics study. One of them, light-driven sodium pump

rhodopsin (NaR) structure was determined. The other one we have solved the first crystal structure of a unique class light-

driven chloride pump (ClR) from Nonlabens marinus S1-08, at resolutions of 1.57 Å. Like structured Halorhodopsin (HR),

ClR can transfer chloride ion from extracellular to cytosol. Although both ClR and HR are same light-driven chloride pump

rhodopsin, we found some evidences that ClR and HR are different in structure and mechanism. The structures reveal two

chloride-binding sites, one around the protonated Schiff base and the other on a cytoplasmic loop. We identify a “3 omega

motif ” formed by three non-consecutive aromatic amino acids that is correlated with the B-C loop orientation. Detailed CIR

structural analyses with functional studies in E. coli reveal the chloride ion transduction pathway. Our results help understand

the molecular mechanism and physiological role of ClR and provide a structural basis for optogenetic applications.

Biography

Hyun-Soo Cho has research interest in understanding the structural and functional role of various proteins involved in cancer and immune diseases. He is

specialized in X-ray crystallography to solve protein structures with other biophysical and biochemical techniques including Cryo_EM recently. His ongoing research

projects include various enzymes and receptors especially G-Protein Coupled Receptor (GPCR) related with cancer and immune system.

hscho8@yonsei.ac.kr

Hyun-Soo Cho, J Proteomics Bioinform 2017, 10:8(Suppl)

DOI: 10.4172/0974-276X-C1-0100

Figure 1:

Chloride ion conductance pathway in ClR