Nucleic acid binding activity of human Cockayne syndrome B protein and identification of Ca(2+) as a novel metal cofactor.

ABSTRACT: The Cockayne syndrome group B protein (CSB) is a member of the SWI/SNF2 subgroup of Superfamily 2 ATPases/nucleic acid translocases/helicases and is defective in the autosomal recessive segmental progeroid disorder Cockayne syndrome. This study examines the ATP-dependent and the ATP-independent biochemical functions of human CSB. We show that Ca(2+) is a novel metal cofactor of CSB for ATP hydrolysis, mainly through the enhancement of k(cat), and that a variety of biologically relevant model nucleic acid substrates can function to activate CSB ATPase activity with either Mg(2+) or Ca(2+) present. However, CSB lacked detectable ATP-dependent helicase and single- or double-stranded nucleic acid translocase activities in the presence of either divalent metal. CSB was found to support ATP-inde

SUBMITTER: Berquist BR 

PROVIDER: S-EPMC2728148 | biostudies-literature | 2009 Sep

REPOSITORIES: biostudies-literature