1Y9X

Solution structure of Archaeon DNA-binding protein ssh10b

Summary for 1Y9X

• Entry DOI: 10.2210/pdb1y9x/pdb
• Descriptor: DNA/RNA-binding protein Alba 1 (1 entity in total)
• Functional Keywords: dna binding, archaea, dna binding protein
• Biological source: Sulfolobus shibatae
• Cellular location: Cytoplasm: P60848
• Total number of polymer chains: 2
• Total formula weight: 21150.81

Authors

Cui, Q.,Tong, Y.,Wang, J. (deposition date: 2004-12-16, release date: 2005-06-21, Last modification date: 2024-05-22)

Primary citation

Fang, X.,Cui, Q.,Tong, Y.,Feng, Y.,Shan, L.,Huang, L.,Wang, J.
A stabilizing alpha/beta-hydrophobic core greatly contributes to hyperthermostability of archaeal [P62A]Ssh10b.
Biochemistry, 47:11212-11221, 2008

PubMed Abstract: The hyperthermophilic Ssh10b from Sulfolobus shibatae is a member of the Sac10b family, which has been postulated to play a role in chromosomal organization in Archaea. Ssh10b is capable of significantly constraining negative DNA supercoils at elevated temperatures. In this study, the solution structure of the dimeric P62A mutant Ssh10b ([P62A]Ssh10b) was determined by multidimensional NMR spectroscopy. The backbone 15N dynamics, H/D exchange with and without the denaturant GdmSCN, and chemical and thermal denaturation experiments were performed to investigate the molecular basis of high thermostability of [P62A]Ssh10b. Data analysis has revealed an alpha/beta-hydrophobic core consisting of two alpha-helices and one beta-sheet which are stabilized by cooperative hydrophobic and hydrogen-bonding interactions. This stabilizing alpha/beta-hydrophobic core of [P62A]Ssh10b exhibiting highly restricted internal motions is composed of residues having highly protected amide protons which exchange with solvent mostly by means of a global unfolding process. The K40N mutation greatly destabilizes the mutant [P62A]Ssh10b because this mutation disturbs the packing of alpha-helix against the beta-sheet reducing the stability of the alpha/beta-hydrophobic core in the mutant protein. In comparison with homologous mesophilic and thermophilic proteins, it can be presumed that the stabilizing alpha/beta-hydrophobic core in the [P62A]Ssh10b structure greatly contributes to the high thermostability of the protein.

PubMed: 18821773
DOI: 10.1021/bi8007593

Experimental method

SOLUTION NMR