Table 1

Summary of subfamilies identified within the NSS family.1

Subfamily Designation
Description
Number of Sequences

Osmolytes
Two distinct groups of GABA transporters (11 and 12, respectively). Also includes: creatine (6), taurine (9), and betaine transporters (6). Two remain ORFans.
46
Biogenic amines
Two distinct groups of dopamine transporters (13 and 6, respectively). Also includes: norepinephrine (13), epinephrine (1), and serotonin (11) transporters.
44
Renal system
Only 7 sequences are characterized, of which: 5 are isolated from the renal system; 1 is an intestinal brush border proline transporter; and the last was found in the brain. Due to the location of the branch point, the sequences highlighted in dark purple in Figure 1 are also included; however, no experimental evidence is available to confirm or refute this.
24
Amino acid #1
Mainly includes proline (5) and glycine (10) transporters; 3 are generically annotated as "amino acid" transporters.
18
Amino acid #2
3 generically annotated as "amino acid" transporters and 2 ORFans.
5
Prokaryotic
Bacterial and archaeal transporters (includes LeuTAa). Nearly all are from genome sequencing projects and lack robust biophysical characterization of functional specificity.
44

1 An exact summary of all experimentally characterized and ORFan sequences are provided in Additional file 1.

Livesay et al. BMC Bioinformatics 2007 8:397   doi:10.1186/1471-2105-8-397