Elongation factor SII contacts the 3'-end of RNA in the RNA polymerase II elongation complex

• Type of Material: Article
• Authors: Wade Powell, Emory University; Blaine Bartholomew, Southern Illinois University; Daniel Reines, Emory University
• Language: English
• Date: 1996-09-13
• Publisher: American Society for Biochemistry and Molecular Biology
• Publication Version: Final Published Version
• Copyright Statement: © 1996 by The American Society for Biochemistry and Molecular Biology, Inc.
• Final Published Version (URL): http://dx.doi.org/10.1074/jbc.271.37.22301
• Title of Journal or Parent Work: Journal of Biological Chemistry
• ISSN: 0021-9258
• Volume: 271
• Issue: 37
• Start Page: 22301
• End Page: 22304
• Grant/Funding Information: This work was supported by Grant GM46331 from the National Institutes of Health.
• Keywords: Life Sciences & Biomedicine; INITIATION FACTOR-ALPHA; FACILITATED TRANSCRIPT CLEAVAGE; ACTIVE-SITE; TERNARY COMPLEXES; ESCHERICHIA-COLI; Biochemistry & Molecular Biology; TFIIS; Science & Technology
• Research Categories: Biology, Molecular; Chemistry, Biochemistry

Abstract

Elongation factor SII (also known as TFIIS) is an RNA polymerase II binding protein that allows bypass of template arrest sites by activating a nascent RNA cleavage reaction. Here we show that SII contacts the 3'-end of nascent RNA within an RNA polymerase II elongation complex as detected by photoaffinity labeling. Photocross-linking was dependent upon the presence of SII, incorporation of 4-thio-UMP into RNA, and irradiation and was sensitive to treatment by RNase and proteinase. A transcriptionally active mutant of SII lacking the first 130 amino acids was also cross-linked to the nascent RNA, but SII from Saccharomyces cerevisiae, which is inactive in concert with mammalian RNA polymerase II, failed to become photoaffinity labeled. SII-RNA contact was not detected after a labeled oligoribonucleotide was released from the complex by nascent RNA cleavage, demonstrating that this interaction takes place between elongation complex-associated but not free RNA. This shows that the 3'-end of RNA is near the SII binding site on RNA polymerase II and suggests that SII may activate the intrinsic RNA hydrolysis activity by positioning the transcript in the enzyme's active site.