This Article Full Text (PDF) Other Versions of this Article: MCB.00906-08v1 28/21/6547    most recent Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Reprints and Permissions Copyright Information Books from ASM Press MicrobeWorld Google Scholar Articles by Champion, E. A. Articles by Baserga, S. J. PubMed PubMed Citation Articles by Champion, E. A. Articles by Baserga, S. J.

 Previous Article  |  Next Article 

Mol. Cell. Biol. doi:10.1128/MCB.00906-08
Copyright (c) 2008, American Society for Microbiology and/or the Listed Authors/Institutions. All Rights Reserved.

A direct interaction between the Utp6 HAT domain and a specific peptide in Utp21 is essential for efficient pre-rRNA processing

Departments of Genetics, Molecular Biophysics and Biochemistry, Chemistry, and Therapeutic Radiology, Yale University, New Haven, CT, 06520, USA

^* To whom correspondence should be addressed. Email: susan.baserga{at}yale.edu.

	Abstract

The SSU processome is a ribosome biogenesis intermediate that assembles from its subcomplexes onto the pre-18S rRNA with yet unknown order and structure. Here, we investigate the architecture of the UtpB subcomplex of the SSU processome, focusing on the interaction between the HAT domain of Utp6 and a specific peptide in Utp21. We present a comprehensive map of the interactions within the UtpB subcomplex, and further show that the N-terminal domain of Utp6 interacts with Utp18, while the HAT domain interacts with Utp21. Using a panel of point and deletion mutants of Utp6, we show that an intact HAT domain is essential for efficient pre-rRNA processing and cell growth. Further investigation of the Utp6-Utp21 interaction using both genetic and biophysical methods shows that the HAT domain binds a specific peptide ligand in Utp21, the first example of a HAT domain peptide ligand, with a dissociation constant of 10 µM.