Rpb4 and Rpb7, the fourth and the seventh largest subunits of RNA polymerase II, form a heterodimer in Saccharomyces cerevisiae. To identify the site of interaction between these subunits, we constructed truncation mutants of both these proteins and carried out yeast two hybrid analysis. Deletions in the amino and carboxyl terminal domains of Rpb7 abolished its interaction with Rpb4. In comparison, deletion of up to 49 N-terminal amino acids of Rpb4 reduced its interaction with Rpb7. Complete abolishment of interaction between Rpb4 and Rpb7 occurred by truncation of 1-106, 1-142, 108-221, 172-221 or 198-221 amino acids of Rpb4. Use of the yeast two-hybrid analysis in conjunction with computational analysis of the recently reported crystal structure of Rpb4/Rpb7 sub-complex allowed us to identify regions previously not suspected to be involved in the functional interaction of these proteins. Taken together, our results have identified the regions that are involved in interaction between the Rpb4 and Rpb7 subunits of S. cerevisiae RNA polymerase II in vivo.
|Original language||English (US)|
|Number of pages||8|
|Journal||Biochemical and Biophysical Research Communications|
|State||Published - Jul 8 2005|
Bibliographical noteFunding Information:
This study was supported by a grant from University Grants Commission. We are very grateful to Dr. Erica Golemis (FCCC, Philadelphia, Pennsylvania) for the yeast two hybrid strain and vectors. We thank Dr. Debasis Mohanty for his invaluable help with the bioinformatics analysis and use of the bioinformatics facility at National Institute of Immunology is acknowledged. We thank Dr. N. Raghuram and Dr. Jyoti Jaiswal for helpful comments on the manuscript. We also thank Dr. Rajnish Kaushik, Dr. Shibani Mitra-Kaushik, and Veenu Aishwarya, and the past and present members of the laboratory for all their help and suggestions.
- RNA polymerase II