Annotating non-coding RNAs with Rfam.

Non-coding RNA (ncRNA) genes produce a functional RNA product, rather than a translated protein. The range and importance of such genes is only recently apparent, with known ncRNAs participating in a wide range of structural, regulatory, and catalytic roles within the cell. Like protein-coding genes, multiple sequence alignments of families of ncRNAs tell us much about their structure and function, and enable the formulation of statistical models for the detection of related sequences. Rfam is a database of families of ncRNAs, represented by structure-annotated multiple sequence alignments and covariance models.