Table 2.

The Eight Completely Sequenced Organisms Used in this Study

Abbrev.	Organism	Phylogeny			Size (Mb)	Proteins	Reference
Ecol	Escherichia coli	Bacteria	Proteobacteria	gamma subdivision	4.653	4283	Blattner et al. 1997
Hinf	Haemophilus influenzae	Bacteria	Proteobacteria	gamma subdivision	1.830	1703	Fleischmann et al. 1995
Hpyl	Helicobacter pylori	Bacteria	Proteobacteria	epsilon subdivision	1.667	1566	Tomb et al. 1997
Mjan	Methanococcus jannaschii	Archaea	Euryarchaeota	Methanococcales	1.739	1736	Bult et al. 1996
Mgen	Mycoplasma genitalium	Bacteria	Firmicutes	Bacillus/Clostridium	.58	468	Fraser et al. 1995
Mpne	Mycoplasma pneumoniae	Bacteria	Firmicutes	Bacillus/Clostridium	.816	677	Himmelreich et al. 1996
Scer	Saccharomyces cerevisiae	Eukaryota	Fungi	Ascomycota	12.068	5932	Goffeau et al. 1997
Syne	Synechocystis sp.	Bacteria	Cyanobacteria	Chroococcales	3.573	3168	Kaneko et al. 1996

This table lists the currently published microbial genomes, discussed in the text, from the TIGR web site (http://www.tigr.org/tdb/mdb/mdb.html). The first column lists the abbreviations that are used for the figures in this paper, corresponding to the genome name in the second column. Column three shows the top three levels of the phylogenetic lineage of the organisms as shown in the NCBI Taxonomy Browser (http://www.ncbi.nlm.nih.gov/Taxonomy/tax.html), which is sufficient to locate the taxa on the traditional tree. The size of the complete genome of the particular organism is shown in the fourth column with the total number of proteins in the organism listed on the next column. The final column lists the original publication citation for each of the genomes.