Table 1.
Identification of 26 S-mycothiolated proteins in C. diptheriae DSM43989 using shotgun LC-MS/MS analysis after exposure to 400 μM NaOCl for 30 min.
| Protein | Locus Tag | Function | Cys-SSM | Cys-SSM peptide sequence | Ortholog and conservation* of Cys with -SSM in Mtb |
|---|---|---|---|---|---|
| Antioxidant enzymes | |||||
| DirA (AhpC) | DIP1420 | 2-Cys peroxiredoxin | Cys61* # active site | (K)DFTFVC61PTEIAAFGK(L) | Rv2428* |
| Protein synthesis | |||||
| RplC | DIP0473 | 50S ribosomal protein L3 | Cys154* # | (R)VGGIGAC154ATPGR(V) | Rv0701* |
| RpsM | DIP0546 | 30S ribosomal protein S13 | Cys86* # | (K)IEIGC86YQGLR(H) | Rv3460c* |
| Pth | DIP0897 | Peptidyl-tRNA hydrolase | Cys49 | (K)ASGAVIEVGGC49R(V) | Rv1014c |
| DIP1398 | DIP1398 | RNA methyltransferase | Cys376* nucleophile | (R)AIAQSGPQAAIHIGC376DPATFAR(D) | Rv2689c* |
| Energy metabolism | |||||
| DIP1726 | DIP1726 | Putative glucanotransferase | Cys45 | (R)SLGVC45FGNEDEPATDHEPLTGPMPSEDQIR(Y) | Rv1781c |
| Gap | DIP1310 | Glyceraldehyde 3-phosphate DH | Cys153* # active site | (K)HNIISNASC153TTNCLAPMAK(V) | Rv1436* |
| DIP1796 | DIP1796 | Putative ribose/galactose isomerase | Cys143 | (R)RIDILC143EYER(T) | Rv2465c |
| DIP0655 | DIP0655 | Putative ribokinase | Cys171 | (R)GTVVVNLAPVIDVDRDC171LLR(A) | — |
| GlpD | DIP2237 | Putative glycerol-3-phosphate DH | Cys10 | (K)SHC10TFNPDYYQDVWQR(F) | Rv2249c |
| Ndh | DIP1217 | NADH dehydrogenase | Cys159 | (R)AEmC159EDPKER(E) | Rv1854c |
| Biosynthesis of amino acids | |||||
| ThrA | DIP1036 | Homoserine dehydrogenase | Cys243 | (R)VTYADVYC243EGISK(I) | Rv1294 |
| DIP0511 | DIP0511 | 4-hydroxy-tetrahydrodipicolinate synthase | Cys141 | (R)AVAAATSLPVIAYDIPVC141VHTK(L) | — |
| DapA | DIP1464 | 4-hydroxy-tetrahydrodipicolinate synthase | Cys161 | (R)SVVPIAPDTLC161R(L) | Rv2753c |
| DIP0974 | DIP0974 | Putative aminotransferase | Cys138 | (R)C138DAPHELPNDDIDLVFINSPSNPTGR(V) | Rv1178 |
| GlnA1 | DIP1644 | Glutamine synthetase | Cys220 | (R)QHPEC220GTGSQQEINYR(F) | — |
| LeuB | DIP1105 | 3-isopropylmalate dehydrogenase | Cys130 | (R)EGTEGLYC130GNGGTLR(E) | Rv2995c |
| Biosynthesis of nucleotides | |||||
| DIP1631 | DIP1631 | Uncharacterized protein | Cys43* | (R)IAVQPGGC43SGLR(Y) | Rv2204c* |
| GuaB | DIP0580 | Inosine-5′-monophosphate DH | Cys317* # active site | (K)VGIGPGSIC317TTR(V) | Rv3410c* |
| PurA | DIP2063 | Adenylosuccinate synthetase | Cys423 | (R)DQTIVC423HDVMEA(-) | Rv0357c |
| Other functions | |||||
| DIP0913 | DIP0913 | Uncharacterized protein | Cys22 | (K)ERPTAGPQLYPVTC22EAVVSAIR(A) | — |
| DIP1026 | DIP1026 | Conserved ATP-binding protein | Cys75 | (R)IC75LEADLGPVR(F) | Rv1278 |
| DIP1102 | DIP1102 | Putative uncharacterized protein | Cys441 | (R)LLSAC441PESGLYK(G) | — |
| DIP1250 | DIP1250 | M18 family aminopeptidase | Cys401* | (K)AGSSHQVFVGNNSVPC401GSTIGPITATR(L) | Rv0800* |
| DIP1287 | DIP1287 | UPF0210 protein DIP1287 | Cys324 | (K)GGMMAC324SR(V) | — |
| GlmS | DIP1700 | Glutamine-fructose-6-P aminotransferase | Cys74 | (K)VQALEQELETSPMPQSC74LGIGHTR(W) | Rv3436c |
The S-mycothiolated proteins were identified using shotgun LC-MS/MS analysis and the Scaffold proteome software based on the mass increase of 484 Da (for -SSM) at Cys peptides. The table lists the Uniprot-accession number, protein name, conservation of the protein and the S-mycothiolated Cys residue in M. tuberculosis (Mtb) and the Cys-SSM peptide sequence. Conserved Cys residues are indicated with (*) and are shown in bold-face. Cys residues that were previously identified S-mycothiolated or S-bacillithiolated in C. glutamicum, M. smegmatis or S. aureus are indicated with (#).