Table 2. The 69 diatom MTs that are putatively derived from red algae, and red and/or green algae, clustered based on similar functions.
| Cluster ID | Size | Putative function | MT family | Outgroup | Algal origin | HECTAR output |
| A02NE02 | 2 | Protein translocase subunit secA | IISP | Prokaryote | R | - |
| A02NE04 | 1 | Sodium bicarbonate cotransporter 3 | AE | Prokaryote | R | CHL |
| A02NE06 | 9 | High-affinity nitrate transporter | MFS | Prokaryote | R | SA |
| A02NE19 | 2 | Magnesium and cobalt efflux protein | HCC | Prokaryote | R | SP |
| A03NE28 | 2 | Signal sequence-binding protein | IISP | Prokaryote | R | - |
| A04NE01 | 1 | S-adenosylmethionine mitochondrial carrier protein | MC | Metazoa | R | - |
| A04NE02 | 1 | Solute carrier family 25 member 36 | MC | Metazoa | R | - |
| A04NE03 | 1 | HCO3 - transporter family | AE | Metazoa | R | SA |
| A02NE09 | 3 | Uncharacterized sodium-dependent transporter | BASS | Prokaryote | R+G | SP |
| A03NE27 | 3 | K+ efflux antiporter chloroplastic | CPA2 | Prokaryote | R+G | CHL |
| A02NE01 | 1 | Adenosine 3-phospho 5-phosphosulfate transporter 1 | DMT | Metazoa | R/G | - |
| A02NE05 | 3 | Chloride channel protein CLC-f | ClC | Prokaryote | R/G | MIT |
| A02NE07 | 4 | Inner membrane protein chloroplastic | Oxa1 | Prokaryote | R/G | CHL |
| A02NE10 | 1 | Protein grpE | MPT | Prokaryote | R/G | - |
| A02NE11 | 2 | S-adenosylmethionine mitochondrial carrier protein | MC | Fungi | R/G | SP |
| A02NE12 | 1 | Glutathione S-transferase DHAR2 | CLIC | Prokaryote | R/G | SA |
| A02NE13 | 2 | Low affinity tryptophan permease | HAAAP | Prokaryote | R/G | SA |
| A02NE14 | 1 | Sodium-dependent phosphate transport protein chloroplastic | MFS | Prokaryote | R/G | SP |
| A02NE15 | 5 | Folate/biopterin transporter | FBT | Prokaryote | R/G | SA |
| A02NE16 | 2 | YggT/hypothetical protein | YggT | Prokaryote | R/G | SP |
| A02NE17 | 4 | ABC transporter D family member chloroplastic | ABC | Prokaryote | R/G | MIT |
| A02NE18 | 2 | ABC transporter G family member 7 | ABC | Metazoa | R/G | SP |
| A02NE22 | 1 | ATP synthase gamma chloroplastic | F-ATPase | Prokaryote | R/G | CHL |
| A03NE14 | 1 | Anion exchanger | AE | Metazoa | R/G | - |
| A03NE23 | 3 | Sodium bile acid cotransporter | BASS | Prokaryote | R/G | SP |
| A03NE26 | 3 | Permease of the drug/metabolite transporter | DMT | Prokaryote | R/G | CHL |
| A03NE36 | 5 | ABC transporter ATP-binding protein | ABC | Prokaryote | R/G | - |
| A03NE48 | 3 | K+ efflux antiporter chloroplastic | CPA2 | Prokaryote | R/G | SP |
Shown for each cluster is the identifier (Cluster ID), number of proteins within the cluster (Size), the putative function, the classification of MT family based on TransportDB, the outgroup used in phylogeny sorting, the putative algal origin of the proteins, i.e., Red (R), Red or Green (R/G), and Red and Green (R+G), and the protein target prediction using HECTAR, in which “CHL” denotes proteins targeting to chloroplast/plastid, “MIT” denotes proteins targeting to mitochondrion, “SP” denotes presence of signal peptide, “SA” denotes presence of Type II signal anchor, “-” denotes no N-terminal target peptide found. None of these proteins show evidence of mitochondrion-targeting. The abbreviation of MT family follows Table S1, according to http://www.membranetransport.org/.