Ricin removes an adenine from a specific portion of the 28S rRNA. This modification leads to reduced
binding of elongation factors to the ribosome and reduced binding.
While the structure of an eukaryotic ribosome is known, it is not at the level of detail to be able to precisely map this location. What is known about the location of the depurination is:
--The depurination occurs in the sacrin-ricin loop of the 28S subunit at a GAGA sequence at A4324 (eukaryotic numbering)
--L3 and L6 bind to this same loop
