Table 2.

The Summary of the Ortholog Groups Showing the Number of ATP-Binding Proteins, the Operon Structure, and Known Functions

Ortholog groupGram-negative bacteriaGram-positive bacteriaCyanobacteriaArchaeaKnown functions (substrates)
EcoHinHpyMgeMpnSynMja
1-112512271sn-glycerol-3-phosphate, maltose/  maltodextrin, putrescine/  spermidine, sulfate/thiosulfate,

 molybdate, thiamin
1-242151glycine betaine/l-proline, taurine,

 nitrate
1-31112?
1-41?
29311 d-ribose, d-galactose, d-xylose,

l-arabinose
3-14222322involved in cell division?
3-21112?
3-36211glutamate/asparate, glutamine,  arginine, histidine
3-41phosphonate
3-5242branched-chain amino acids
3-6(1)(1)(1)(1)?
3-7111131phosphate
4-11263221(2)oligopeptide, dipeptide, nickel
4-2(2)?
5-14211112vitamin B12, ferrichrome, iron(III)  dicitrate, ferric enterobactin
5-2122manganese
5-314422cobalt
67833210multidrug resistance?
731151capsule polysaccharide export  (ABC-2)
8(4)(4)(1)(2)(1)?
9(1)(1)(1)?
1011heme export?
113(ABC-2?)
12(1)?
13(1)?
 Total78421816175417

[i] Most of the transporter genes form operon structures, as indicated by shaded cells. Numbers in parentheses represent functional classes that are apparently different from ABC transporters.