2BKY: Crystal Structure Of The Alba1:alba2 Heterodimer From Sulfolobus Solfataricus

Organisms growing at elevated temperatures face a particular challenge to maintain the integrity of their genetic material. All thermophilic and hyperthermophilic archaea encode one or more copies of the Alba (Sac10b) gene. Alba is an abundant, dimeric, highly basic protein that binds cooperatively and at high density to DNA. Sulfolobus solfataricus encodes a second copy of the Alba gene, and the Alba2 protein is expressed at approximately 5% of the level of Alba1. We demonstrate by NMR, ITC, and crystallography that Alba2 exists exclusively as a heterodimer with Alba1 at physiological concentrations and that heterodimerization exerts a clear effect upon the DNA packaging, as observed by EM, potentially by changing the interface between adjacent Alba dimers in DNA complexes. A functional role for Alba2 in modulation of higher order chromatin structure and DNA condensation is suggested.
PDB ID: 2BKYDownload
MMDB ID: 91058
PDB Deposition Date: 2005/2/22
Updated in MMDB: 2011/10
Experimental Method:
x-ray diffraction
Resolution: 1.7  Å
Source Organism:
Similar Structures:
Biological Unit for 2BKY: tetrameric; determined by author and by software (PISA)
Molecular Components in 2BKY
Label Count Molecule
Proteins (4 molecules)
Dna/rna-binding Protein Alba 1(Gene symbol: albA)
Molecule annotation
Dna/rna-binding Protein Alba 2(Gene symbol: SSO_RS04800)
Molecule annotation
Chemicals (5 molecules)
* Click molecule labels to explore molecular sequence information.

Citing MMDB