TABLE 1.
Overview of the genetic complement of a minimal B. subtilis cell
| Function | No. of proteins (no. of essential proteins)a | No. of RNA genes (no. of essential genes)a | Figure(s) |
|---|---|---|---|
| Information processing | 197 (125) | 119 (2) | |
| DNA replication | 18 (15) | ||
| Chromosome maintenance | 13 (9) | ||
| Transcription | 8 (5) | ||
| RNA folding and degradation | 6 (1) | ||
| Aminoacyl-tRNA synthetases | 24 (23) | 4 | |
| Ribosomal proteins | 53 (35) | ||
| rRNA and tRNA | 116 (0) | ||
| rRNA/tRNA maturation and modification | 31 (13) | 1 (1) | |
| Ribosome maturation and assembly | 9 (6) | ||
| Translation factors | 11 (9) | ||
| Translation/other | 5 (2) | 1 (0) | |
| Protein secretion | 12 (5) | 1 (1) | 2 |
| Proteolysis, protein quality control, chaperones | 7 (2) | ||
| Metabolism | 218 (59) | ||
| Central carbon metabolism | 26 (4) | 3 | |
| Respiration/energy | 16 (2) | 3 | |
| Amino acids | 30 (1)b | 3 | |
| Nucleotides/phosphate | 36 (11) | 2, 5 | |
| Lipids | 19 (17) | 6 | |
| Cofactors | 62 (14)b | ||
| General components of ECF transporters | 3 (0)b | 4, 7 | |
| NAD | 5 (4) | 7 | |
| FAD | 2 (1)b | 7 | |
| Pyridoxal phosphate | 2 (0) | 7 | |
| Biotin | 1 (0)b | 7 | |
| Thiamine | 2 (0)b | 7 | |
| Lipoate | 4 (1) | 7 | |
| Coenzyme A | 9 (1) | 7 | |
| S-Adenosylmethionine | 1 (1) | 7 | |
| Folate | 13 (1) | 8 | |
| Heme | 12 (0) | 8 | |
| Menaquinone | 8 (5) | 9 | |
| Metals/iron-sulfur clusters | 29 (10) | 2, 7 | |
| Cell division | 81 (52) | ||
| Cell wall synthesis | 55 (41) | ||
| Amino acid precursor | 11 (10) | 10 | |
| Undecaprenyl phosphate | 13 (10) | 10 | |
| Lipid II biosynthesis | 12 (11) | 10 | |
| Peptidoglycan polymerization | 5 (1) | 10 | |
| Wall teichoic acid | 9 (8) | 11 | |
| Lipoteichoic acid | 5 (1) | 6 | |
| Coordination | 22 (9) | ||
| Signaling | 4 (2) | 2 | |
| Integrity of the cell | 16 (5) | ||
| Protection | 8 (4) | 2 | |
| Repair/genome integrity | 8 (1) | ||
| Other/unknown | 11 (2) | ||
| Total minimal genome | 523 (243) | 119 (2) |
a
The numbers of proteins and RNAs required for each function are listed. Numbers in parentheses indicate the numbers of proteins and RNAs that are essential in the context of B. subtilis 168.
b
Tryptophan, riboflavin, biotin, and thiamine are transported by transporters of the ECF (energy-coupling factor) family. The three general components are shared among all these transporters. They are listed separately with the cofactors.