FIG. 1.

Comparison of the genome organization for phages B3 and Mu. The genomes of B3 and Mu are shown as thick lines and are drawn approximately to scale, with tick marks at 1-kb intervals. ORFs are shown as boxes; their positions were derived from GenBank accession numbers AF083977 and NC_000929 for the Mu genome and this work for B3 (GenBank accession number AF232233). The direction of transcription is indicated by an arrow; in addition, genes transcribed rightward are shown above the line, and those transcribed leftward are positioned below the line. Relevant Mu genes are identified by their gene names or sequential genome gp numbers, and functions if known. The predicted B3 gene functions shown were deduced from the known functions of homologous genes in Mu or other phages; for B3 genes with Mu homologues, the identity of the homologous Mu gene is also given.