5L8Z

Structure of thermostable DNA-binding HU protein from micoplasma Spiroplasma melliferum

Replaces:  5CVXReplaces:  4N1V

Summary for 5L8Z

• Entry DOI: 10.2210/pdb5l8z/pdb
• Descriptor: DNA-binding protein, SODIUM ION (3 entities in total)
• Functional Keywords: thermostable, dna-binding, hu-protein, spiroplasma melliferum, histone-like, nap, dna binding protein
• Biological source: Spiroplasma melliferum KC3
• Total number of polymer chains: 1
• Total formula weight: 10428.89

Authors

Boyko, K.M.,Gorbacheva, M.A.,Rakitina, T.V.,Korzhenevskiy, D.A.,Kamashev, D.E.,Vanyushkina, A.A.,Lipkin, A.V.,Popov, V.O. (deposition date: 2016-06-09, release date: 2016-06-22, Last modification date: 2024-01-10)

Primary citation

Boyko, K.M.,Rakitina, T.V.,Korzhenevskiy, D.A.,Vlaskina, A.V.,Agapova, Y.K.,Kamashev, D.E.,Kleymenov, S.Y.,Popov, V.O.
Structural basis of the high thermal stability of the histone-like HU protein from the mollicute Spiroplasma melliferum KC3.
Sci Rep, 6:36366-36366, 2016

PubMed Abstract: The three-dimensional structure of the histone-like HU protein from the mycoplasma Spiroplasma melliferum KC3 (HUSpm) was determined at 1.4 Å resolution, and the thermal stability of the protein was evaluated by differential scanning calorimetry. A detailed analysis revealed that the three-dimensional structure of the HUSpm dimer is similar to that of its bacterial homologues but is characterized by stronger hydrophobic interactions at the dimer interface. This HUSpm dimer interface lacks salt bridges but is stabilized by a larger number of hydrogen bonds. According to the DSC data, HUSpm has a high denaturation temperature, comparable to that of HU proteins from thermophilic bacteria. To elucidate the structural basis of HUSpm thermal stability, we identified amino acid residues potentially responsible for this property and modified them by site-directed mutagenesis. A comparative analysis of the melting curves of mutant and wild-type HUSpm revealed the motifs that play a key role in protein thermal stability: non-conserved phenylalanine residues in the hydrophobic core, an additional hydrophobic loop at the N-terminal region of the protein, the absence of the internal cavity present at the dimer interface of some HU proteins, and the presence of additional hydrogen bonds between the monomers that are missing in homologous proteins.

PubMed: 27808161
DOI: 10.1038/srep36366

Experimental method

X-RAY DIFFRACTION (1.4 Å)