Table 2.
Ab initio LC–MS/MS identification of selected proteins present in the secretome of pure A. thiooxidans and the metasecretome of mixed A. thiooxidans/A. ferrooxidans sulfur cultures
| Spot no. | Protein ID (NCBInr protein BLAST) | pI | MW [kDa] | Peptides | ID prob. (%) | Comments/observations |
|---|---|---|---|---|---|---|
| A. thiooxidans DSM 17318 secretome protein identification | ||||||
| 1 | YP_002220838.1| lipoprotein, putative [Acidithiobacillus ferrooxidans ATCC 53993] | 9.4 | 10.2 | (K)AEEANEKVER(M) | 100 | Lipoprotein named Licanantase in this study |
| (K)ANAAQSTATDALSK(A) | (SignalP 3.0 Server) SignalP Prediction: signal peptide probability—0.996 | |||||
| (K)ANAAQSTADQAmSTANSANQK(A) | ||||||
| Signal anchor probability—0.001. | ||||||
| 3 | YP_002219721.1| hypothetical protein Lferr_1276 [Acidithiobacillus ferrooxidans ATCC 53993] | 9.1 | 33.4 | (R)TAQEYR(S) | 100 | Non-classically secreted protein (Secretome 2.0 Server) |
| (R)EDNDPRAKDR(E) | ||||||
| 4 | YP_002514952.1| glyceraldehyde-3-phosphate dehydrogenase (phosphorylating) [Thioalkalivibrio sp. HL-EbGR7] | 6.2 | 35.7 | (K)TVDGPSAKDWR(G) | 100 | (TatP 1.0 Server) potential Tat signal peptide |
| Most likely cleavage site between pos. 22 and 23: AIA-KE | ||||||
| (K)YAGEKIVSAASCTTNCLAPIAK(V) | ||||||
| Non-classically secreted protein (Secretome 2.0 Server) | ||||||
| 5 | YP_002218536.1| protein TolA [Acidithiobacillus ferrooxidans ATCC 53993] | 10.1 | 32.9 | (K)QLAAQAAQAAAAAR(A) | 100 | Non-classically secreted protein (Secretome 2.0 Server) |
| (K)AAQEKATARKAAQEK(A) | ||||||
| 6 | YP_002302972.1| pentapeptide repeat-containing protein, IcmE [Coxiella burnetii CbuG_Q212] | 9.2 | 106.4 | (R)FDTPPTVR(V) | 100 | A. thiooxidans DSM 17318 draft genome showed a truncated icmE gene that, based on proteomic analysis, is able to generate a protein of 45.7 kDa |
| (TatP 1.0 Server) potential Tat signal peptide | ||||||
| Most likely cleavage site between pos. 40 and 41: AGL-QS | ||||||
| Non-classically secreted protein (Secretome 2.0 Server) | ||||||
| 7 | YP_002220287.1| hypothetical protein Lferr_1859 [Acidithiobacillus ferrooxidans ATCC 53993] | 4.5 | 25.5 | (K)EQVSLTLMRTLALEGIKLR(E) | 100 | No signal peptide |
| (R)SEPTFGEK(S) | ||||||
| (R)MRQGLMQFTSSR(S) | Anomalous protein molecular mass | |||||
| (K)PAPINPEPAEKPIR(F) | ||||||
| 8 | YP_002219232.1| 3-isopropylmalate dehydratase, large subunit [Acidithiobacillus ferrooxidans ATCC 53993] | 5.7 | 50.1 | (K)AQAEAEGLDR(I) | 100 | No signal peptide |
| (K)DMVLAIIGK(M) | ||||||
| (K)AASVKVAMVVPGSGLVK(A) | ||||||
| 9 | YP_002220770.1| phosphate-selective porin O and P [Acidithiobacillus ferrooxidans ATCC 53993] | 4.9 | 42.2 | (K)WDGAYTSK(G) | 100 | Omp40-like protein |
| (K)FRVPVGMER(T) | ||||||
| (R)SMNQTLGADR(S) | Non-classically secreted protein (Secretome 2.0 Server) | |||||
| (R)QVDSWNVGAR(G) | ||||||
| (K)YLFAGMVGYK(L) | ||||||
| (K)GTAVPGVTYNFQYK(W) | 42.3% amino acid identity to Omp40 (YP_002427116) from A. ferrooxidans ATCC 23270 | |||||
| (R)TQFSGNDLWFIQR(S) | ||||||
| (R)VQLNYVIPTGASGFR(H) | ||||||
| (R)TQFSGNDLWFIQR(S) | ||||||
| (K)GTAVPGVTYNFQYK(W) | ||||||
| (K)GIGSHTGNSGIQDAEINFAFIPEVQLK(V) | ||||||
| 10 | YP_002220770.1| phosphate-selective porin O and P [Acidithiobacillus ferrooxidans ATCC 53993] | 4.9 | 42.2 | (K)WDGAYTSK(G) | 96 | Omp40-like protein |
| (K)GTAVPGVTYNFQYK(W) | ||||||
| (R)TQFSGNDLWFIQR(S) | Non-classically secreted protein (Secretome 2.0 Server) | |||||
| (R)VQLNYVIPTGASGFR(H) | ||||||
| 42.3% amino acid identity to Omp40 (YP_002427116) from A. ferrooxidans ATCC 23270 | ||||||
| (K)YLFAGmVGYK(L) | ||||||
| A. thiooxidans DSM 17318/A. ferroxidans DSM 16786 metasecretome protein identification | ||||||
| 2 | YP_002220838.1| lipoprotein, putative [Acidithiobacillus ferrooxidans ATCC 53993] | 9.4 | 10.2 | (K)ANAAQSTATDALSK(A) | 100 | Lipoprotein named Licanantase in this study |
| (SignalP 3.0 Server) SignalP Prediction: signal peptide probability—0.996 | ||||||
| Signal anchor probability—0.001 | ||||||
| 11 | YP_002220838.1| lipoprotein, putative [Acidithiobacillus ferrooxidans ATCC 53993] | 9.4 | 10.2 | (K)ANAAQSTATDALSK(A) | 100 | Lipoprotein named Licanantase in this study |
| (SignalP 3.0 Server) SignalP Prediction: signal peptide probability—0.996 | ||||||
| Signal anchor probability—0.001 | ||||||
| 12 | YP_002220838.1| lipoprotein, putative [Acidithiobacillus ferrooxidans ATCC 53993] | 9.4 | 10.2 | (K)ANAAQSTATDALSK(A) | 100 | Lipoprotein named Licanantase in this study |
| (SignalP 3.0 Server) SignalP Prediction: signal peptide probability—0.996 | ||||||
| Signal anchor probability—0.001 | ||||||
| 13 | YP_002220770.1| phosphate-selective porin O and P [Acidithiobacillus ferrooxidans ATCC 53993] | 4.9 | 42.2 | (K)WDGAYTSK(G) | 55 | Omp40-like protein |
| Non-classically secreted protein (Secretome 2.0 Server) | ||||||
| 42.3% amino acid identity to Omp40 (YP_002427116) from A. ferrooxidans ATCC 23270 | ||||||
| 14 | YP_608509.1| hypothetical protein PSEEN2944 [Pseudomonas entomophila L48] | 4.8 | 46.2 | (R)LSLSTSFADR(I) | 100 | (SignalP 3.0 Server) SignalP Prediction: signal peptide probability—0.998 |
| Signal anchor probability—0.001 | ||||||
| 15 | YP_002219159.1| cytochrome c biogenesis protein transmembrane region [Acidithiobacillus ferrooxidans ATCC 53993] | 9.3 | 65.0 | (R)VNVTASDAASR(H) | 100 | (SignalP 3.0 Server) SignalP Prediction: signal peptide probability—0.971 |
| (R)mDVETYDNPR(V) | Signal anchor probability—0.027 | |||||