Relative Stabilities of Conserved and Non-Conserved Structures in the OB-Fold Superfamily
Department of Molecular and Cell Biology, University of Connecticut, Storrs, CT 06269, USA
*
Author to whom correspondence should be addressed.
Int. J. Mol. Sci. 2009, 10(5), 2412-2430; https://doi.org/10.3390/ijms10052412
Received: 1 April 2009 / Revised: 16 May 2009 / Accepted: 19 May 2009 / Published: 22 May 2009
(This article belongs to the Special Issue Protein Folding 2009)
The OB-fold is a diverse structure superfamily based on a β-barrel motif that is often supplemented with additional non-conserved secondary structures. Previous deletion mutagenesis and NMR hydrogen exchange studies of three OB-fold proteins showed that the structural stabilities of sites within the conserved β-barrels were larger than sites in non-conserved segments. In this work we examined a database of 80 representative domain structures currently classified as OB-folds, to establish the basis of this effect. Residue-specific values were obtained for the number of Cα-Cα distance contacts, sequence hydrophobicities, crystallographic B-factors, and theoretical B-factors calculated from a Gaussian Network Model. All four parameters point to a larger average flexibility for the non-conserved structures compared to the conserved β-barrels. The theoretical B-factors and contact densities show the highest sensitivity.Our results suggest a model of protein structure evolution in which novel structural features develop at the periphery of conserved motifs. Core residues are more resistant to structural changes during evolution since their substitution would disrupt a larger number of interactions. Similar factors are likely to account for the differences in stability to unfolding between conserved and non-conserved structures.
View Full-Text
▼
Show Figures
This is an open access article distributed under the Creative Commons Attribution License
MDPI and ACS Style
Guardino, K.M.; Sheftic, S.R.; Slattery, R.E.; Alexandrescu, A.T. Relative Stabilities of Conserved and Non-Conserved Structures in the OB-Fold Superfamily. Int. J. Mol. Sci. 2009, 10, 2412-2430. https://doi.org/10.3390/ijms10052412
AMA Style
Guardino KM, Sheftic SR, Slattery RE, Alexandrescu AT. Relative Stabilities of Conserved and Non-Conserved Structures in the OB-Fold Superfamily. International Journal of Molecular Sciences. 2009; 10(5):2412-2430. https://doi.org/10.3390/ijms10052412
Chicago/Turabian StyleGuardino, Kaitlyn M.; Sheftic, Sarah R.; Slattery, Robert E.; Alexandrescu, Andrei T. 2009. "Relative Stabilities of Conserved and Non-Conserved Structures in the OB-Fold Superfamily" Int. J. Mol. Sci. 10, no. 5: 2412-2430. https://doi.org/10.3390/ijms10052412
Find Other Styles
Search more from Scilit