Characterization of the cold-adapted -alpha-tubulin from the psychrophilic ciliate Euplotes focardii
Tubulin dimers of psychrophilic organisms can polymerize into microtubules at temperatures below 4 degrees C, at which non-cold-adapted microtubules disassemble. This capacity requires specificities in the structure and/or in the posttranslational modifications of the tubulin subunits. A contributio...
| Published in: | Extremophiles |
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| Main Authors: | , |
| Other Authors: | , |
| Format: | Article in Journal/Newspaper |
| Language: | English |
| Published: |
2002
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| Subjects: | |
| Online Access: | http://hdl.handle.net/11581/116426 https://doi.org/10.1007/s00792-002-0268-5 https://link.springer.com/article/10.1007/s00792-002-0268-5 |
| Summary: | Tubulin dimers of psychrophilic organisms can polymerize into microtubules at temperatures below 4 degrees C, at which non-cold-adapted microtubules disassemble. This capacity requires specificities in the structure and/or in the posttranslational modifications of the tubulin subunits. A contribution to the knowledge of these specificities was provided by the finding that the amino acid sequence of the alpha-tubulin of the Antarctic ciliate Euplotes focardii contains substitutions that, in addition to conferring an increased hydrophobicity to the molecule, modify sites that are involved in alpha-/alpha-tubulin lateral contacts between protofilaments. At the level of the coding sequence, the alpha-tubulin gene of E. focardii revealed an A+T content appreciably higher than in its homologs in ciliates of temperate waters. This was interpreted as an adaptation to favor DNA strand separation in an environment which is energetically adverse. |
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