Table 1.
Classification of thermotolerant genes and characterization of their Tn10-inserted mutants in Z. mobilis TISTR 548
| Category | Tn10-inserted gene | Function | Protein typea | Growth at high temperature compared with that of parental strainb | Sensitivity to ethanolc | Effect of MgCld2 | |||
|---|---|---|---|---|---|---|---|---|---|
| 38 °C | 39 °C | 39.5 °C | 2.0% (v/v) | 2.5% (v/v) | |||||
| (WT, TISTR548) | ++++ | +++++ | +++ | ++++ | ++++ | − | |||
| General | ZZ6_0707 | Glucose sorbosone dehydrogenase | S | + | + | − | ++++ | ++++ | − |
| Metabolism (Group A) | ZZ6_1376 | 5,10-methylenetetrahydrofolate reductase | S | ++++ | ++++ | + | +++ | +++ | +++ |
| Membrane | ZZ6_1146 | Glucosamine/fructose 6-phosphate aminotransferase | M | + | + | − | ++ | ++ | +++ |
| Stabilization (Group B) | ZZ6_0929 | Glycosyltransferase group 1 | S | + | − | − | ++++ | + | ++++ |
| ZZ6_0923 | Phospholipase D/transphosphatidylase | M | − | − | − | – | − | – | |
| ZZ6_1551 | Squalene hopene cyclase (Shc) | S | − | − | − | + | − | +++ | |
| ZZ6_1046 | Tol/Pal system component TolQ | M | + | + | − | ++ | ++ | − | |
| ZZ6_1043 | Tol/Pal system component TolB | S | + | + | + | ++++ | ++++ | − | |
| ZZ6_1254 | Protein export membrane protein SecD | M | − | − | − | ++ | + | ++ | |
| ZZ6_1477 | Preprotein translocase subunit Tim44 | M | − | − | − | ++++ | ++++ | − | |
| ZZ6_0158 | Autotransporter secretion inner membrane protein TamB | M | + | − | − | ++ | ++ | ++++ | |
| ZZ6_1210 | Competence protein ComEC | M | − | − | − | + | + | +++ | |
| ZZ6_0840 | Hypothetical transmembrane protein | M | − | − | − | ++++ | +++ | ++ | |
| ZZ6_0541 | Hypothetical transmembrane protein | M | ++++ | +++ | + | ++ | ++ | ++ | |
| Transporter (Group C) | ZZ6_1289 | Putative Fe2+/Mn2+ transporter | M | − | − | − | +++ | +++ | − |
| DNA repair (Group D) | ZZ6_0616 | DNA repair protein RadC | S | ++++ | +++ | + | +++ | +++ | − |
| ZZ6_0934 | Exonuclease VII (XseA) | S | − | − | − | +++ | +++ | − | |
| ZZ6_0681 | DNA repair protein RadA | S | + | + | − | +++ | +++ | ++ | |
| tRNA/rRNA modification (Group E) | ZZ6_0023 | tRNA/rRNA methyltransferase (SpoU) | S | +++ | ++ | ++ | ++ | ++ | ++ |
| Protein quality control (Group F) | ZZ6_1659 | Zn-dependent peptidase | S | ++++ | +++ | ++ | ++++ | ++++ | − |
| ZZ6_0980 | Serin protease DegP | S | − | − | − | − | − | + | |
| Translation control (Group G) | ZZ6_0702 | ATP-dependent helicase HrpB | S | − | − | − | + | − | − |
| Cell division (Group H) | ZZ6_0979 | ParA/MinD-like ATPase | S | − | − | − | ++ | ++ | − |
| Transcriptional regulation (Group I) | ZZ6_0019 | Trp repressor-binding protein WrbA | S | − | − | − | +++ | ++ | − |
| Others | ZZ6_0962 | Pseudogene | (S) | + | + | − | ++++ | ++++ | ++ |
| ZZ6_0861 | Hypothetical protein | S | + | + | − | ++ | ++ | − | |
aProtein type was described as described in "Methods" sections.”S” and “M” mean soluble protein and membrane protein, respectively
bThe growth of representative of isolated mutants was compared to that of the parental strain on 3% YPD plates at 38, 39, and 39.5 °C. The number of “+” indicates the degree of cell growth at high temperature compared to that of the parental strain, while “−” indicates no growth
cThe tolerance of representative of isolated mutants to ethanol was determined by comparison of growth on 3% YPD plates containing 2.0 and 2.5% (v/v) ethanol. The number of “+” indicates the degree of cell growth at 30 °C under the ethanol stress condition compared to that of the parental strain, while “−” indicates no growth
dThe effect of MgCl2 on the growth of representative of isolated mutants was determined by comparison of growth in 3% YPD liquid medium containing 20 mM MgCl2 at 39.5 °C. The number of “+” indicates the following degree of cell growth compared to that of the growth in the absence of MgCl2: ++, P < 0.05; +++, P < 0.01; ++++, P < 0.001. “−” indicates no significant improvement of growth by the addition of MgCl2