Sample sequencing of a Salmonella typhimurium LT2 lambda library: comparison to the Escherichia coli K12 genome

As part of the ongoing sequencing of the complete Salmonella typhimurium LT2 genome, a partly ordered set of 416 lambda clones has been developed, representing over 90% of the genome. The average insert size is 17 kb. Sequences were obtained from both ends of each clone in this set. A total of over 600 kb of sequence has been deposited in the genome survey sequence section of GenBank. This resource of clones is available from the Salmonella Genome Stock Center. A preliminary comparison with the Escherichia coli K12 genome indicates that there are likely to be many hundred insertion deletion events, encompassing more than one gene, that distinguish these genomes. Fully 30% of the S. typhimurium sequences have no close homologs in the GenBank database.