Open AccessAn Abundant DNA Binding Protein from the Hyperthermophilic Archaeon Sulfolobus shibatae Affects DNA Supercoiling in a Temperature-Dependent Fashion
Author(s) -
Hong Xue,
Rong Guo,
Yunfei Wen,
Danxu Liu,
Li Huang
Publication year - 2000
Publication title -
journal of bacteriology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.652
H-Index - 246
eISSN - 1067-8832
pISSN - 0021-9193
DOI - 10.1128/jb.182.14.3929-3933.2000
Subject(s) - dna supercoil , sulfolobus , biology , thermophile , dna , archaea , sulfolobus acidocaldarius , z dna , electrophoretic mobility shift assay , dna binding protein , biochemistry , biophysics , microbiology and biotechnology , dna replication , gene , transcription factor , enzyme
The DNA binding protein Ssh10b, a member of the Sac10b family, has been purified from the hyperthermophilic archaeonSulfolobus shibatae . Ssh10b constitutes about 4% of the cellular protein. Electrophoretic mobility shift assays showed that Ssh10b first bound a double-stranded DNA fragment with an estimated binding size of ∼∼12 bp, forming distinct shifts, until the DNA was coated with the protein. Binding of more Ssh10b resulted in the formation of smears of lower mobilities. The migration pattern of the smearing Ssh10b-DNA complexes was affected by temperature, whereas that of complexes associated with the distinct shifts was not. Interestingly, Ssh10b was capable of constraining negative DNA supercoils in a temperature-dependent fashion. While the ability of the protein to constrain supercoils was weak at 25°C, it was enhanced substantially at 45°C or higher temperatures (up to 80°C). Taken together, our data suggest that archaeal proteins of the Sac10b family may affect the topology of chromosomal DNA in thermophilic archaea at their growth temperatures.