Table 1.
Peptides observed by mass spectrometry following cell-free expression from wild-type and synthetic genome templates
| Genome templates | ||||||
| Protein | Peptide sequence† | No. of spectra | Notes | WT øX174 | cryptX174 | kleenX174 |
| 75 | fMSIITPK | 22 | N-terminal formylmethionine | + | + | — |
| A | fMQGVEFDNGDMYVDGHK | 3 | N-terminal formylmethionine | — | — | + |
| A | WFLENEK | 7 | + | — | — | |
| A or A* | VTVADVLAAQPVTTNLLK | 4 | + | — | + | |
| B | RDEIEAGK | 5 | — | — | + | |
| C | None detected | — | — | — | ||
| D | fMSQVTEQSVRFQTALASIK | 33 | N-terminal formylmethionine | + | — | + |
| E | None detected | — | — | — | ||
| F | EIQYLNAK | 3 | + | — | + | |
| G | LVLTSVTPASSAPVLQTPK | 7 | + | + | — | |
| G | EIICLQPLK | 8 | — | — | + | |
| H | FGAIAGGIASALAGGAMSK | 9 | + | + | — | |
| H | fMFGAIAGGIASALAGGAMSK | 11 | N-terminal formylmethionine | + | + | — |
| H | LLDLVGLGGK | 11 | + | — | — | |
| H | MQLDNQK | 2 | + | — | — | |
| H | SAIQGSNVPNPDEAAPSFVSGAMAK | 5 | + | + | — | |
| J | GARLWYVGGQQF | 31 | + | — | — | |
| K | LLLCDLSPSTNDSVKN | 5 | + | — | + | |
†
øX174-specific peptides observed from shotgun mass spectrometry measurement of proteins produced in a Protein synthesis Using Recombinant Elements (PURE) expression reaction. Only peptides with P value ≤ 0.05 and with ≥2 observed spectra are reported. The protein search database contained both E. coli and øX174 protein sequences corresponding to the appropriate phage genome (WT øX174, cryptX174, or kleenX174).