From: ncbi-disc-admin@ncbi.nlm.nih.gov on behalf of Vivek Anantharaman [ananthar@ncbi.nlm.nih.gov] Sent: Monday, September 24, 2001 4:20 PM To: ncbi-seminar@ara.nlm.nih.gov Subject: CBB seminar - Tuesday 25th 11 AM Tuesday September 25th 11:00 am. ConfN6S (South Conference Room, Natcher 6 Floor) Evolutionary history of RNA Metabolism Vivek Anantharaman Cells from all extant organisms synthesize an array of RNAs, using DNA or RNA templates, through a reaction that is catalyzed by RNA polymerases. RNA metabolism constitutes an inseparable part of the basic processes in the Central Dogma of molecular biology, namely transcription, translation and secretion as well as numerous other cellular systems that employ RNAs in various capacities. We conducted an computational analysis of proteins involved in RNA metabolism, which encompasses those proteins that more or less directly interact with every known kind of RNA from the time it is synthesized by the RNA polymerase until its ultimate degradation. In order to obtain a synthetic view of RNA metabolism and reconstruct its development right from the earliest phases prior to the LCA, through the diversification of the major lineages of life, to the terminal branches of the Tree of Life that are available to us, a large scale computational analysis of the RNA metabolism proteins, from 30 complete genomes from the three kingdoms of life, was conducted. The computational analysis was chiefly based on detection of statistically significant similarities through sequence and structure comparisons, determination of orthologous and paralogous relationships between proteins and use of contextual information coming from domain fusions, operon organization and phyletic patterns. This allowed the definition of the major transitions and relative temporal order in the evolution of these processes (Transcription, Translation and Secretion, Splicing and Processing, Post transcriptional Gene regulation, Modification, and Capping and Adenylation), as well as to obtain gleanings of some of the earliest phases of the evolution of life itself. 80 orthologous RNA metabolism related protein groups were traced to the LCA, suggesting that even before the radiation from LCA, RNA metabolism had already differentiated into several distinct functional complexes. The analysis also enabled systematization of the vast amounts of information available regarding these process through the genome sequencing efforts and generation of structural and functional predictions that might aid in future experimental investigations of RNA metabolism. Vivek Anantharaman, PhD National Center for Biotechnology Information National Library of Medicine National Institutes of Health,Bldg. 38A, Rm. N507A, 8600 Rockville pike, Bethesda, MD 20894, USA Voice: (301)443-1194 Email: vanantha@ncbi.nlm.nih.gov