Table 2.

Summary of functional predictions made for representative members of each phylogenetic cluster (Figure 1).

Cluster #	Proposed Functions
1	Transport of sulfur-based compounds; FeS cluster assembly.
2	Transport of peptides/amino acids/glycerate. Nitrogen-based compound transport;
3	Arsenate/arsenite resistance; Oxidative, heat and metabolic stress response.
4	Transport of sulfur-based compounds.
5	Transport of sulfur-based compounds/ions/peptides/amino acids; FeS cluster assembly; Stress response.
6	Transport of carbon or sulfur-based compounds.
7	Stress response and virulence.
8	Transport of sulfur-based compounds.
9–11	None identified
12	Transport of amino acids.
13	Transport of sulfur-based compounds/Iron/peptides/amino acids.
14	Transport of sulfur-based compounds.
15	Transport of sulfur-based compounds; Extrusion of sulfite.