New Cysteine-Rich Ice-Binding Protein Secreted from Antarctic Microalga, Chloromonas sp.
Many microorganisms in Antarctica survive in the cold environment there by producing ice-binding proteins (IBPs) to control the growth of ice around them. An IBP from the Antarctic freshwater microalga, Chloromonas sp., was identified and characterized. The length of the Chloromonas sp. IBP (ChloroI...
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ftdoajarticles:oai:doaj.org/article:bc8bf4e2a0c940be98900563f411176b 2023-05-15T13:45:34+02:00 New Cysteine-Rich Ice-Binding Protein Secreted from Antarctic Microalga, Chloromonas sp. Woongsic Jung Robert L Campbell Yunho Gwak Jong Im Kim Peter L Davies EonSeon Jin 2016-01-01T00:00:00Z https://doi.org/10.1371/journal.pone.0154056 https://doaj.org/article/bc8bf4e2a0c940be98900563f411176b EN eng Public Library of Science (PLoS) http://europepmc.org/articles/PMC4838330?pdf=render https://doaj.org/toc/1932-6203 1932-6203 doi:10.1371/journal.pone.0154056 https://doaj.org/article/bc8bf4e2a0c940be98900563f411176b PLoS ONE, Vol 11, Iss 4, p e0154056 (2016) Medicine R Science Q article 2016 ftdoajarticles https://doi.org/10.1371/journal.pone.0154056 2022-12-31T03:31:24Z Many microorganisms in Antarctica survive in the cold environment there by producing ice-binding proteins (IBPs) to control the growth of ice around them. An IBP from the Antarctic freshwater microalga, Chloromonas sp., was identified and characterized. The length of the Chloromonas sp. IBP (ChloroIBP) gene was 3.2 kb with 12 exons, and the molecular weight of the protein deduced from the ChloroIBP cDNA was 34.0 kDa. Expression of the ChloroIBP gene was up- and down-regulated by freezing and warming conditions, respectively. Western blot analysis revealed that native ChloroIBP was secreted into the culture medium. This protein has fifteen cysteines and is extensively disulfide bonded as shown by in-gel mobility shifts between oxidizing and reducing conditions. The open-reading frame of ChloroIBP was cloned and over-expressed in Escherichia coli to investigate the IBP's biochemical characteristics. Recombinant ChloroIBP produced as a fusion protein with thioredoxin was purified by affinity chromatography and formed single ice crystals of a dendritic shape with a thermal hysteresis activity of 0.4±0.02°C at a concentration of 5 mg/ml. In silico structural modeling indicated that the three-dimensional structure of ChloroIBP was that of a right-handed β-helix. Site-directed mutagenesis of ChloroIBP showed that a conserved region of six parallel T-X-T motifs on the β-2 face was the ice-binding region, as predicted from the model. In addition to disulfide bonding, hydrophobic interactions between inward-pointing residues on the β-1 and β-2 faces, in the region of ice-binding motifs, were crucial to maintaining the structural conformation of ice-binding site and the ice-binding activity of ChloroIBP. Article in Journal/Newspaper Antarc* Antarctic Antarctica Directory of Open Access Journals: DOAJ Articles Antarctic The Antarctic PLOS ONE 11 4 e0154056 |
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topic |
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Medicine R Science Q Woongsic Jung Robert L Campbell Yunho Gwak Jong Im Kim Peter L Davies EonSeon Jin New Cysteine-Rich Ice-Binding Protein Secreted from Antarctic Microalga, Chloromonas sp. |
topic_facet |
Medicine R Science Q |
description |
Many microorganisms in Antarctica survive in the cold environment there by producing ice-binding proteins (IBPs) to control the growth of ice around them. An IBP from the Antarctic freshwater microalga, Chloromonas sp., was identified and characterized. The length of the Chloromonas sp. IBP (ChloroIBP) gene was 3.2 kb with 12 exons, and the molecular weight of the protein deduced from the ChloroIBP cDNA was 34.0 kDa. Expression of the ChloroIBP gene was up- and down-regulated by freezing and warming conditions, respectively. Western blot analysis revealed that native ChloroIBP was secreted into the culture medium. This protein has fifteen cysteines and is extensively disulfide bonded as shown by in-gel mobility shifts between oxidizing and reducing conditions. The open-reading frame of ChloroIBP was cloned and over-expressed in Escherichia coli to investigate the IBP's biochemical characteristics. Recombinant ChloroIBP produced as a fusion protein with thioredoxin was purified by affinity chromatography and formed single ice crystals of a dendritic shape with a thermal hysteresis activity of 0.4±0.02°C at a concentration of 5 mg/ml. In silico structural modeling indicated that the three-dimensional structure of ChloroIBP was that of a right-handed β-helix. Site-directed mutagenesis of ChloroIBP showed that a conserved region of six parallel T-X-T motifs on the β-2 face was the ice-binding region, as predicted from the model. In addition to disulfide bonding, hydrophobic interactions between inward-pointing residues on the β-1 and β-2 faces, in the region of ice-binding motifs, were crucial to maintaining the structural conformation of ice-binding site and the ice-binding activity of ChloroIBP. |
format |
Article in Journal/Newspaper |
author |
Woongsic Jung Robert L Campbell Yunho Gwak Jong Im Kim Peter L Davies EonSeon Jin |
author_facet |
Woongsic Jung Robert L Campbell Yunho Gwak Jong Im Kim Peter L Davies EonSeon Jin |
author_sort |
Woongsic Jung |
title |
New Cysteine-Rich Ice-Binding Protein Secreted from Antarctic Microalga, Chloromonas sp. |
title_short |
New Cysteine-Rich Ice-Binding Protein Secreted from Antarctic Microalga, Chloromonas sp. |
title_full |
New Cysteine-Rich Ice-Binding Protein Secreted from Antarctic Microalga, Chloromonas sp. |
title_fullStr |
New Cysteine-Rich Ice-Binding Protein Secreted from Antarctic Microalga, Chloromonas sp. |
title_full_unstemmed |
New Cysteine-Rich Ice-Binding Protein Secreted from Antarctic Microalga, Chloromonas sp. |
title_sort |
new cysteine-rich ice-binding protein secreted from antarctic microalga, chloromonas sp. |
publisher |
Public Library of Science (PLoS) |
publishDate |
2016 |
url |
https://doi.org/10.1371/journal.pone.0154056 https://doaj.org/article/bc8bf4e2a0c940be98900563f411176b |
geographic |
Antarctic The Antarctic |
geographic_facet |
Antarctic The Antarctic |
genre |
Antarc* Antarctic Antarctica |
genre_facet |
Antarc* Antarctic Antarctica |
op_source |
PLoS ONE, Vol 11, Iss 4, p e0154056 (2016) |
op_relation |
http://europepmc.org/articles/PMC4838330?pdf=render https://doaj.org/toc/1932-6203 1932-6203 doi:10.1371/journal.pone.0154056 https://doaj.org/article/bc8bf4e2a0c940be98900563f411176b |
op_doi |
https://doi.org/10.1371/journal.pone.0154056 |
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PLOS ONE |
container_volume |
11 |
container_issue |
4 |
container_start_page |
e0154056 |
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1766227486123753472 |