VIR: a computational tool for analysis of immunoglobulin sequences.

In this paper a microcomputer software named VIR (Variable domains of the Immune Receptors) is reported. This package can be used in sequence studies of immunoglobulin variable domains. The main features of the VIR software in the sequences management are: (1) ease of information recovery/extraction from amino acid sequences; and (2) its capability to obtain multiple sequence alignments with predefined characteristics (i.e. specie and/or specificity). As an analytical tool, the VIR package employs such multiple sequence alignments to compute: (1) tables showing amino acid frequencies; (2) three variability indexes; (3) identity matrices; (4) random samples; and (5) sequences with possible canonical structures. Thus the software reported here is proposed as a useful tool to carry out detailed studies of immunoglobulin variable domains.