title: Cockayne syndrome group B protein enhances elongation by RNA polymerase II.
abstract: Cockayne syndrome (CS) is characterized by impaired physical and mental development. Two complementation groups, CSA and CSB, have been identified. Here we report that the CSB gene product enhances elongation by RNA polymerase II. CSB stimulated the rate of elongation on an undamaged template by a factor of about 3. A thymine-thymine cyclobutane dimer located in the template strand is known to be a strong block to transcription. Addition of CSB to the blocked polymerase resulted in addition of one nucleotide to the nascent transcript. Finally, addition of transcription factor IIS is known to cause polymerase blocked at a thymine-thymine cyclobutane dimer to digest its nascent transcript, and CSB counteracted this transcript shortening action of transcription factor IIS. Thus a deficiency in transcription elongation may contribute to the CS phenotype.
authors.affiliation: Department of Biochemistry and Biophysics, University of North Carolina School of Medicine, Chapel Hill, NC 27599-7260, USA.
authors.forename: C P
authors.initials: CP
authors.lastname: Selby
authors.forename: A
authors.initials: A
authors.lastname: Sancar
mesh_terms: D001483:Base Sequence; D003057:Cockayne Syndrome / Q000235:genetics*; D004247:DNA / Q000737:chemistry / Q000378:metabolism; D004265:DNA Helicases / Q000235:genetics / Q000378:metabolism*; D045643:DNA Repair Enzymes; D004789:Enzyme Activation; D006801:Humans; D000075223:Poly-ADP-Ribose Binding Proteins; D011740:Pyrimidine Dimers; D012313:RNA / Q000737:chemistry; D012319:RNA Polymerase II / Q000378:metabolism*; D013379:Substrate Specificity; D013698:Templates, Genetic; D014157:Transcription Factors / Q000378:metabolism; D035165:Transcription Factors, General; D014158:Transcription, Genetic; D035602:Transcriptional Elongation Factors
chemical_list: D000075223:Poly-ADP-Ribose Binding Proteins; D011740:Pyrimidine Dimers; D014157:Transcription Factors; D035165:Transcription Factors, General; D035602:Transcriptional Elongation Factors; C018648:transcription factor S-II; D012313:RNA; D004247:DNA; D012319:RNA Polymerase II; D004265:DNA Helicases; C078673:ERCC6 protein, human; D045643:DNA Repair Enzymes