Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Intrinsically disordered protein from a pathogenic mesophile Mycobacterium tuberculosis adopts structured conformation at high temperature.
Show others and affiliations
2008 (English)In: Proteins: Structure, Function, and Bioinformatics, ISSN 0887-3585, E-ISSN 1097-0134, Vol. 71, no 3, p. 1123-33Article in journal, Editorial material (Refereed) Published
Abstract [en]

Compared to eukaryotes, the occurrence of "intrinsically disordered" or "natively unfolded" proteins in prokaryotes has not been explored extensively. Here, we report the occurrence of an intrinsically disordered protein from the mesophilic human pathogen Mycobacterium tuberculosis. The Histidine-tagged recombinant Rv3221c biotin-binding protein is intrinsically disordered at ambient and physiological growth temperatures as revealed by circular dichroism and Fourier transform infrared (FTIR) spectroscopic studies. However, an increase in temperature induces a transition from disordered to structured state with a folding temperature of approximately 53 degrees C. Addition of a structure inducing solvent trifluoroethanol (TFE) causes the protein to fold at lower temperatures suggesting that TFE fosters hydrophobic interactions, which drives protein folding. Differential Scanning Calorimetry studies revealed that folding is endothermic and the transition from a disordered to structured state is continuous (higher-order), implying existence of intermediates during folding process. Secondary structure analysis revealed that the protein has propensity to form beta-sheets. This is in conformity with FTIR spectrum that showed an absorption peak at wave number of 1636 cm(-1), indicative of disordered beta-sheet conformation in the native state. These data suggest that although Rv3221c may be disordered under ambient or optimal growth temperature conditions, it has the potential to fold into ordered structure at high temperature driven by increased hydrophobic interactions. In contrast to the generally known behavior of other intrinsically disordered proteins folding at high temperature, Rv3221c does not appear to oligomerize or aggregate as revealed through numerous experiments including Congo red binding, Thioflavin T-binding, turbidity measurements, and examining molar ellipticity as a function of protein concentration. The amino acid composition of Rv3221c reveals that it has 24% charged and 54.9% hydrophobic amino acid residues. In this respect, this protein, although belonging to the class of intrinsically disordered proteins, has distinct features. The intrinsically disordered state and the biotin-binding feature of this protein suggest that it may participate in many biochemical processes requiring biotin as a cofactor and adopt suitable conformations upon binding other folded targets.

Place, publisher, year, edition, pages
2008. Vol. 71, no 3, p. 1123-33
National Category
Biological Sciences
Identifiers
URN: urn:nbn:se:kth:diva-259210DOI: 10.1002/prot.21798PubMedID: 18004752OAI: oai:DiVA.org:kth-259210DiVA, id: diva2:1350768
Available from: 2019-09-12 Created: 2019-09-12 Last updated: 2019-09-12

Open Access in DiVA

No full text in DiVA

Other links

Publisher's full textPubMed
In the same journal
Proteins: Structure, Function, and Bioinformatics
Biological Sciences

Search outside of DiVA

GoogleGoogle Scholar

doi
pubmed
urn-nbn

Altmetric score

doi
pubmed
urn-nbn
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf