id	author	title	date	pages	extension	mime	words	sentences	flesch	summary	cache	txt
cord-315616-pvt0amth	Poole, Anthony	Methyl-RNA: an evolutionary bridge between RNA and DNA?	2004-06-17		.txt	text/plain	5623	281	54	Ribonucleotide reductase itself, which synthesises deoxyribonucleotides from ribonucleotides, requires complex protein radical chemistry, and RNA world genomes may have reached their limits of coding capacity well before such complex enzymes had evolved. Even with this gap in the RNA world model, current knowledge suggests the RNA organism that evolved protein synthesis was likely to have been dangerously close to the Eigen limit for RNA, and probably emIn the ¢rst step, a radical is generated at some distance from the active site. By virtue of its non-speci¢c dsRNA methylating activity, this enzyme is hypothesised to have been recruited into methylation of genomic RNA, improving the stability of the genetic material prior to the origin of DNA. The predicted stabilising effect of 2P-O-methylation on genomic RNA argues that the coding capacity of the genome would have increased suf¢ciently for genuinely catalytic proteins such as RNA polymerase, and later ribonucleotide reductase, to arise, paving the way to the DNA world (Figure 4) .	./cache/cord-315616-pvt0amth.txt	./txt/cord-315616-pvt0amth.txt