Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.
Panel (a): a proposed mechanism for the cleavage of a phosphodiester bond in yeast phenylalanine tRNA. The Pb2+ is bound to a specific site on the RNA around the bases U59 and C60. The active species is probably (PbOH)+ which has a pKa of about 7.0. Panel (b): oligosulfones, which contain a dimethylene sulfone group in place of phosphate, no longer form duplexes with Watson–Crick base-pairings but bend and fold more like proteins.
