1. Discovery of bacteriorhodopsins in Haloarchaeal species isolated from Indian solar salterns: deciphering the role of the N-terminal residues in protein folding and functional expression.
- Author
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Verma DK, Baral I, Kumar A, Prasad SE, and Thakur KG
- Subjects
- Bacteriorhodopsins chemistry, Bacteriorhodopsins genetics, Bacteriorhodopsins isolation & purification, Cloning, Molecular, Cluster Analysis, DNA, Archaeal chemistry, DNA, Archaeal genetics, DNA, Ribosomal chemistry, DNA, Ribosomal genetics, Escherichia coli genetics, Escherichia coli metabolism, Haloarcula classification, Haloarcula genetics, Haloarcula metabolism, Halobacteriaceae classification, Halobacteriaceae genetics, Halobacteriaceae metabolism, Haloferax classification, Haloferax genetics, Haloferax metabolism, India, Phylogeny, Protein Conformation, Protein Stability, RNA, Ribosomal, 16S genetics, Recombinant Proteins chemistry, Recombinant Proteins genetics, Recombinant Proteins isolation & purification, Recombinant Proteins metabolism, Sequence Analysis, DNA, Bacteriorhodopsins metabolism, Gene Expression, Haloarcula isolation & purification, Halobacteriaceae isolation & purification, Haloferax isolation & purification, Protein Folding, Water Microbiology
- Abstract
Interesting optical and photochemical properties make microbial rhodopsin a promising biological material suitable for various applications, but the cost-prohibitive nature of production has limited its commercialization. The aim of this study was to explore the natural biodiversity of Indian solar salterns to isolate natural bacteriorhodopsin (BR) variants that can be functionally expressed in Escherichia coli. In this study, we report the isolation, functional expression and purification of BRs from three pigmented haloarchaea, wsp3 (water sample Pondicherry), wsp5 and K1
T isolated from two Indian solar salterns. The results of the 16S rRNA data analysis suggest that wsp3, wsp5 and K1T are novel strains belonging to the genera Halogeometricum, Haloferax and Haloarcula respectively. Overall, the results of our study suggest that 17 N-terminal residues, that were not included in the gene annotation of the close sequence homologues, are essential for functional expression of BRs. The primary sequence, secondary structural content, thermal stability and absorbance spectral properties of these recombinant BRs are similar to those of the previously reported Haloarcula marismortui HmBRI. This study demonstrates the cost-effective, functional expression of BRs isolated from haloarchaeal species using E. coli as an expression host and paves the way for feasibility studies for future applications., (© 2019 The Authors. Microbial Biotechnology published by John Wiley & Sons Ltd and Society for Applied Microbiology.)- Published
- 2019
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