Table 1.
Detection of Cas proteins by LC-MS/MS analysis. Protein extracts (standard growth conditions) were analyzed by 2DLC-MS/MS and GelfreeLC-MS/MS analysis by Cassidy et al. [8]. Depicted are the merged identification results for Cas proteins of the I-B and III-C CRISPR loci. For a protein to be classified as identified, it required the presence of at least two peptides of high confidence (< 1% false discovery rate) of which at least one was unique. Proteins that met the criteria are shaded in grey. Medium confidence (< 5% false discovery rate) search settings were utilized to enable a more complete picture of the possible proteins present within the samples. Cas6b proteins are highlighted in bold.
| Protein Name | ORF Number | Σ Coverage | Σ# Peptides (Unique) | High (medium) Confidence |
|---|---|---|---|---|
| Cas4 | MM_0557 | 22.11 | 3 (2) | 0 (3) |
| Cas2 | MM_0558 | - | - | - |
| Cas1 | MM_0559 | 7.74 | 3 (3) | 1 (2) |
| Cas6bIB | MM_0560 | 2.78 | 1 (1) | 0 (1) |
| Cas3 | MM_0561 | 6.91 | 4 (4) | 1 (3) |
| Cas5 | MM_0562 | 27.59 | 4 (4) | 2 (2) |
| Cas7 | MM_0563 | 44.67 | 12 (12) | 8 (4) |
| Cas8 | MM_0564 | 15.82 | 9 (9) | 5 (4) |
| Cas5 | MM_3353 | 51.28 | 13 (12) | 8 (5) |
| SS | MM_3354 | 67.42 | 5 (5) | 3 (2) |
| Cmr4 | MM_3355 | 46.35 | 11 (11) | 8 (3) |
| Cas10 | MM_3356 | 26.85 | 22 (22) | 12 (10) |
| Cmr6 | MM_3357 | 32.43 | 5 (4) | 1 (4) |
| Cas7 | MM_3358 | 39.07 | 10 (9) | 1 (9) |
| Cas6bIIIC | MM_3359 | 28.27 | 5 (5) | 0 (5) |