Table 11.
Functionally characterized Sco and Mxa proteins
| Protein designation; Sco# or Mxan#, and reference 1 | UniProt Acc# | TC# | Probable or established function |
|---|---|---|---|
|
S. coelicolor
| |||
| MscL; Sco3190 [102] |
Q9KYV5 |
1.A.22.1.10 |
MscL, osmotic adaptation channel that influences sporulation and secondary metabolite production. |
| GlcP1/2; Sco7153; Sco5578 [103] |
Q7BEC4 |
2.A.1.1.35 |
MFS major glucose uptake porters (two identical sequences at the AA level, and having a single substitution on the NT level). |
| MdrA; Sco4007 [104] |
Q9ADP8 |
2.A.1.36.4 |
Putative MDR transporter; may export hydrophobic cationic compounds. |
| PitH1 and 2; Sco4138 and Sco1845 [105] |
Q9KZW3, Q9RJ23 |
2.A.20.1.5 and 6 |
Two putative low-affinity inorganic phosphate (Pi) uptake porters. |
| DasABC: Sco5232-4 (R, M, M). MsiK: Sco4240 (C) [106] |
Q9K489-91,Q9L0Q1 |
3.A.1.1.33 |
DasABC/MsiK; system for the uptake of chitin-degradation products. |
| Agl3EFG porter (R, M, M; Sco7167-Sco7165 [107]; Agl3K (C; unknown) |
Q9FBS7-5 |
3.A.1.1.43 |
Sugar uptake porter; induced by trehalose and melibiose using a GntR transcription factor. May use the MsiK ATPase [106]. |
| MalEFG; Sco2231-Sco2229 (R, M, M) [108]; MalK (C) unknown. |
Q7AKP1, Q9KZ07-8 |
3.A.1.1.44 |
Sugar uptake porter; involved in maltose and maltodextrin uptake. May use the MsiK ATPase [106]. |
| XylFGH. |
O50503-5 |
3.A.1.2.24 |
Xylose uptake porter; transcriptionally regulated by a GntR-type protein, ROK7B7. |
| XylF, Sco6009 (R; 1 N-terminal TMS); | |||
| XylG, Sco6010 (C; ATP-binding, no TMSs); | |||
| XylH, Sco6011 (M; 12 TMSs); [109] | |||
| Probable ABC peptide uptake porter; Sco5476-80 (M, R, M, C, C) [110] |
O86571-5 |
3.A.1.5.34 |
Probably takes up a peptide involved in the regulation of sporulation and secondary metabolite production. |
| Sco5117-Sco5121 (R, M, M, C, C) [111] |
Q9F353-49 |
3.A.1.5.35 |
Probable oligopeptide uptake porter. |
| BldKA-D and Sco5116; Sco5112-6 (M, R, M, C, C) [112] |
Q93IU3-0; Q8CJS2 |
3.A.1.5.36 |
BldKA-D and Sco5116; peptide uptake porter induced by S-adenosylmethionine. |
| DesABC; Sco7499-8, Sco7400 (R, M-M, C) [113] |
Q9L177-9 |
3.A.1.14.12 |
Desferrioxamine B uptake porter. |
| CchCDEF; Sco0497-4 (M, M, C, R) [113] |
Q9RK09-12 |
3.A.1.14.13 |
Ferric iron-coelichelin uptake porter. |
| DesEFGH; Sco2780 (R), Sco1785-7 (C, M, M) [113] |
Q9L07; Q9S215-3 |
3.A.1.14.22 |
Putative ferric iron-desferrioxamine E uptake porter. |
| SclAB; Sco4359-60 (C, M) [114] |
Q9F2Y8-7 |
3.A.1.105.13 |
SclAB transporter; confers acyl depsipeptide (ADEP) resistance. ADEP has antibiotic activity. |
| RagAB; Sco4075-4 (C, M) [115] |
Q7AKK4-5 |
3.A.1.105.14 |
RagAB exporter; involved in both aerial hyphae formation and sporulation. |
| SoxR regulon ABC exporter; Sco7008 (M, C) [116] |
Q9KZE5 |
3.A.1.106.9 |
Putative SoxR-regulated drug exporter; SoxR responds to extracellular redox-active compounds such as actinorhodin. |
| AreABCD; Sco3956-9 (C, M, C’, M’) [117] |
Q9ZBX6-3 |
3.A.1.146.1 |
Putative drug exporter; possibly specific for actinorhodin (ACT) and undecylprodigiosin (RED). |
| H+-PPase; Sco3547 [118] |
Q6BCL0 |
3.A.10.2.2 |
H+-translocating inorganic pyrophosphatase. |
|
M. xanthus
| |||
| MmrA; MXAN_5906 [119] |
Q1CZY0 |
2.A.1.2.83 |
Homologous to drug exporter; possibly involved in amino acid uptake and antimicrobial export. |
| TatABC; MXAN_2960, MXAN_5905-4, [120] |
Q1D854, Q1CZY1-2 |
2.A.64.1.2 |
Twin arginine targeting protein translocase. |
| RfbAB; MXAN_4623-2 (M, C) [121] |
Q1D3I2-3 |
3.A.1.103.4 |
Putative lipopolysaccharide exporter. |
| AbcA; MXAN_1286 (M-C) [122] |
Q1DCT0 |
3.A.1.106.10 |
AbcA; involved in molecular export; required for the autochemotactic process. |
| PilGHI; MXAN_5782-0 (R, C, M) [123] | O30384-6 | 3.A.1.144.5 | Necessary for social motility, pilus assembly and pilus subunit (PilA) export. |
1 M: Membrane component; C: cytoplasmic ATPase energizer; R: Extracytoplasmic solute receptor of an ABC transporter.