摘要 : We report identification and characterization of SSB-like protein from Deinococcus murrayi (DmuSSB). PCR-derived DNA fragment containing the complete structural gene for DmuSSB was cloned and expressed in Escherichia coli. The gen... 展开 We report identification and characterization of SSB-like protein from Deinococcus murrayi (DmuSSB). PCR-derived DNA fragment containing the complete structural gene for DmuSSB was cloned and expressed in Escherichia coli. The gene consisted of an open reading frame of 826 nucleotides encoding a protein of 276 amino acid residues with a calculated molecular weight of 30.14kDa. DmuSSB includes two OB folds per monomer and functions as a homodimer. In fluorescence titrations with poly(dT) DmuSSB bound 27-32nt depending on the salt concentration, and fluorescence was quenched by about 62%. In a complementation assay in E coli, DmuSSB took over the in vivo function of EcoSSB. DmuSSB maintained 100% activity after 120 min incubation at 80 degrees C, with half-lives of 50 min at 95 degrees C, 40 min at 100 degrees C and 35 min at 105 degrees C. DmuSSB is the most thermostable SSB-like protein identified to date, offering an attractive alternative for TaqSSB and TthSSB in their applications for molecular biology methods and for analytical purposes. (c) 2006 Elsevier Inc. All rights reserved. 收起