Cockayne syndrome group B protein has novel strand annealing and exchange activities.

Abstract

Cockayne syndrome (CS) is a rare inherited human genetic disorder characterized by UV sensitivity, severe neurological abnormalities and prageroid symptoms. The CS complementation group B (CSB) protein is involved in UV-induced transcription coupled repair (TCR), base excision repair and general transcription. CSB also has a DNA-dependent ATPase activity that may play a role in remodeling chromatin in vivo. This study reports the novel finding that CSB catalyzes the annealing of complementary single-stranded DNA (ssDNA) molecules with high efficiency, and has strand exchange activity. The rate of CSB-catalyzed annealing of complementary ssDNA is 25-fold faster than the rate of spontaneous ssDNA annealing under identical in vitro conditions and the reaction occurs with a high specificity in the presence of excess non-homologous ssDNA. The specificity and intrinsic nature of the reaction is also confirmed by the observation that it is stimulated by dephosphorylation of CSB, which occurs after UV-induced DNA damage, and is inhibited in the presence of ATPgammaS. Potential roles of CSB in cooperation with strand annealing and exchange activities for TCR and homologous recombination are discussed.

• Authors: Meltem Muftuoglu, Sudha Sharma, Tina Thorslund, Tinna Stevnsner, Martin M Soerensen, Robert M Brosh Jr, Vilhelm A Bohr
• Journal: Nucleic acids research (Nucleic Acids Res) Vol. 34 Issue 1 Pg. 295-304 ( 2006) ISSN: 1362-4962 [Electronic] England
• PMID: 16410611 (Publication Type: Journal Article, Research Support, N.I.H., Extramural, Research Support, Non-U.S. Gov't)

Chemical References

• DNA, Single-Stranded
• Replication Protein A
• Adenosine Triphosphate
• DNA Helicases

Topics

• Adenosine Triphosphate (metabolism)
• Catalysis
• DNA Helicases (metabolism)
• DNA Repair
• DNA, Single-Stranded (metabolism)
• Phosphorylation
• Recombination, Genetic
• Replication Protein A (metabolism)