Over 11 500 complete or nearly complete sequences are now available from th
e Antwerp database on small subunit ribosomal RNA. All these sequences are
aligned with one another on the basis of the adopted secondary structure mo
del, which is corroborated by the observation of compensating substitutions
in the alignment. Literature references, accession numbers and taxonomic i
nformation are also compiled. The database can be consulted via the World W
ide Web at URL http://rrna.uia.ac.be/ssu/.