Many new RNA pseudoknot structures have been detected and proposed in
the past year. Although we are still waiting for the first detailed st
ructure of a pseudoknot, their role in processes such as translational
autoregulation or ribosomal frameshifting has been extensively studie
d and is now well established. Pseudoknot structures appear to play a
pivotal role in small subunit ribosomal RNA and in the noncoding regio
ns of viral RNAs. There are also strong indications that RNA pseudokno
ts are highly suitable structural motifs for the recognition and bindi
ng of proteins.