: Recent advances in gene sequencing have provided complete sequence information for a number of genomes and as a result the amount of data in the sequence databases is growing at an exponential rate. We introduce here a new program, DbW, to automate the update of a functional family-specific multiple alignment that tries to include relevant sequences. The program is based on the use of different sources of information: sequences and annotations in databases. The advantages of DbW are demonstrated using the 20 families of aminoacyl-tRNA synthetases, where DbW detects a maximum of homologous sequences in the SwissProt and SPTREMBL databases. The global specificity of DbW in this test is