Divalent metal ion-induced folding mechanism of RNase H1 from extreme halophilic archaeon Halobacterium sp. NRC-1.
RNase H1 from Halobacterium sp. NRC-1 (Halo-RNase H1) is characterized by the abundance of acidic residues on the surface, including bi/quad-aspartate site residues. Halo-RNase H1 exists in partially folded (I) and native (N) states in low-salt and high-salt conditions respectively. Its folding is a...
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| Format: | Article |
| Language: | English |
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Public Library of Science (PLoS)
2014-01-01
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| Series: | PLoS ONE |
| Online Access: | http://europepmc.org/articles/PMC4182655?pdf=render |
| _version_ | 1819130254031060992 |
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| author | Elias Tannous Shigenori Kanaya |
| author_facet | Elias Tannous Shigenori Kanaya |
| author_sort | Elias Tannous |
| collection | DOAJ |
| description | RNase H1 from Halobacterium sp. NRC-1 (Halo-RNase H1) is characterized by the abundance of acidic residues on the surface, including bi/quad-aspartate site residues. Halo-RNase H1 exists in partially folded (I) and native (N) states in low-salt and high-salt conditions respectively. Its folding is also induced by divalent metal ions. To understand this unique folding mechanism of Halo-RNase H1, the active site mutant (2A-RNase H1), the bi/quad-aspartate site mutant (6A-RNase H1), and the mutant at both sites (8A-RNase H1) were constructed. The far-UV CD spectra of these mutants suggest that 2A-RNase H1 mainly exists in the I state, 6A-RNase H1 exists both in the I and N states, and 8A-RNase H1 mainly exists in the N state in a low salt-condition. These results suggest that folding of Halo-RNase H1 is induced by binding of divalent metal ions to the bi/quad-aspartate site. To examine whether metal-induced folding is unique to Halo-RNase H1, RNase H2 from the same organism (Halo-RNase H2) was overproduced and purified. Halo-RNase H2 exists in the I and N states in low-salt and high-salt conditions respectively, as does Halo-RNase H1. However, this protein exists in the I state even in the presence of divalent metal ions. Halo-RNase H2 exhibits junction ribonuclease activity only in a high-salt condition. A tertiary model of this protein suggests that this protein does not have a quad-aspartate site. We propose that folding of Halo-RNase H1 is induced by binding of divalent metal ion to the quad-aspartate site in a low-salt condition. |
| first_indexed | 2024-12-22T08:56:41Z |
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| id | doaj.art-e579b1caecd446d2ab188c79f8f89ab9 |
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| language | English |
| last_indexed | 2024-12-22T08:56:41Z |
| publishDate | 2014-01-01 |
| publisher | Public Library of Science (PLoS) |
| record_format | Article |
| series | PLoS ONE |
| spelling | doaj.art-e579b1caecd446d2ab188c79f8f89ab92022-12-21T18:31:50ZengPublic Library of Science (PLoS)PLoS ONE1932-62032014-01-0199e10901610.1371/journal.pone.0109016Divalent metal ion-induced folding mechanism of RNase H1 from extreme halophilic archaeon Halobacterium sp. NRC-1.Elias TannousShigenori KanayaRNase H1 from Halobacterium sp. NRC-1 (Halo-RNase H1) is characterized by the abundance of acidic residues on the surface, including bi/quad-aspartate site residues. Halo-RNase H1 exists in partially folded (I) and native (N) states in low-salt and high-salt conditions respectively. Its folding is also induced by divalent metal ions. To understand this unique folding mechanism of Halo-RNase H1, the active site mutant (2A-RNase H1), the bi/quad-aspartate site mutant (6A-RNase H1), and the mutant at both sites (8A-RNase H1) were constructed. The far-UV CD spectra of these mutants suggest that 2A-RNase H1 mainly exists in the I state, 6A-RNase H1 exists both in the I and N states, and 8A-RNase H1 mainly exists in the N state in a low salt-condition. These results suggest that folding of Halo-RNase H1 is induced by binding of divalent metal ions to the bi/quad-aspartate site. To examine whether metal-induced folding is unique to Halo-RNase H1, RNase H2 from the same organism (Halo-RNase H2) was overproduced and purified. Halo-RNase H2 exists in the I and N states in low-salt and high-salt conditions respectively, as does Halo-RNase H1. However, this protein exists in the I state even in the presence of divalent metal ions. Halo-RNase H2 exhibits junction ribonuclease activity only in a high-salt condition. A tertiary model of this protein suggests that this protein does not have a quad-aspartate site. We propose that folding of Halo-RNase H1 is induced by binding of divalent metal ion to the quad-aspartate site in a low-salt condition.http://europepmc.org/articles/PMC4182655?pdf=render |
| spellingShingle | Elias Tannous Shigenori Kanaya Divalent metal ion-induced folding mechanism of RNase H1 from extreme halophilic archaeon Halobacterium sp. NRC-1. PLoS ONE |
| title | Divalent metal ion-induced folding mechanism of RNase H1 from extreme halophilic archaeon Halobacterium sp. NRC-1. |
| title_full | Divalent metal ion-induced folding mechanism of RNase H1 from extreme halophilic archaeon Halobacterium sp. NRC-1. |
| title_fullStr | Divalent metal ion-induced folding mechanism of RNase H1 from extreme halophilic archaeon Halobacterium sp. NRC-1. |
| title_full_unstemmed | Divalent metal ion-induced folding mechanism of RNase H1 from extreme halophilic archaeon Halobacterium sp. NRC-1. |
| title_short | Divalent metal ion-induced folding mechanism of RNase H1 from extreme halophilic archaeon Halobacterium sp. NRC-1. |
| title_sort | divalent metal ion induced folding mechanism of rnase h1 from extreme halophilic archaeon halobacterium sp nrc 1 |
| url | http://europepmc.org/articles/PMC4182655?pdf=render |
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