A-Form (RNA) versus B-Form (DNA)

							  A-Form (RNA) versus B-Form (DNA)
                           A   B



narrow/deep major groove
shallow minor groove
difficult to recognize
Modified Uridines in Eukaryotic tRNA’s




        Useful Website: http://medlib.med.utah.edu/RNAmods/
rRNA Distribution in a Neuron




                               [32P]rRNA probe
      Brain Res. Mol. Brain Res. 20, 305 (1993)


   106–107 ribosomes per human cell!
microRNA and small interfering RNA
         RNA has Structure: tRNA




Proteins recognize DNA sequence and RNA sequence & structure
Common Structural Elements of RNA

 Secondary Structure   Tertiary Structure
    RNA Structure: Tetraloop


                 Bi and Bi+3 are paired

                 Bi+2 stacked

                 B–H···–O–P

                 Analogous to protein b-turn

UUCG Tetraloop