Table 1. The mutagenesis strategy of the histone libraries.
| Category | Original Residue | New Residue | Rationale | H2A (No.) | H2B (No.) | H3 (No.) | H4 (No.) |
|---|---|---|---|---|---|---|---|
| Point mutant | All | Alanine(A) | Remove sidechain | 112 | 113 | 119 | 96 |
| H2A/H2B: 516 | Alanine(A) | Serine(S) | Alter sidechain | 19 | 17 | 16 | 6 |
| H3/H4: 477 | Lysine(K) | Arginine(R) | Mimic deacetyl | 11 | 19 | 16 | 11 |
| Lysine(K) | Glutamine(Q) | Mimic acetyl | 11 | 19 | 16 | 11 | |
| Arginine(R) | Lysine(K) | Mimic demethyl | 10 | 6 | 17 | 14 | |
| Serine(S) | Aspartic Acid(D) | Mimic phosphate | 8 | 19 | 10 | 6 | |
| Threonine(T) | Aspartic Acid(D) | Mimic phosphate | 5 | 11 | 9 | 6 | |
| Tyrosine(Y) | Glutamic Acid (E) | Mimic phosphate | 3 | 5 | 2 | 4 | |
| Lysine(K) | Glutamic acid(E) | Reverse charge | 11 | 19 | 16 | 11 | |
| Arginine(R) | Glutamic acid(E) | Reverse charge | 10 | 6 | 17 | 14 | |
| Aspartic Acid(D) | Arginine(R) | Reverse charge | 3 | 3 | 4 | 3 | |
| Glutamic Acid(E) | Arginine(R) | Reverse charge | 5 | 8 | 7 | 4 | |
| Histidine(H) | Glutamine(Q) | Remove charge | 3 | 2 | 2 | 2 | |
| Aspartic Acid(D) | Asparagine(N) | Remove charge | 3 | 3 | 4 | 3 | |
| Glutamic Acid(E) | Glutamine(Q) | Remove charge | 5 | 8 | 7 | 4 | |
| Asparagine(N) | Aspartic Acid(D) | Add charge | 8 | 3 | 1 | 1 | |
| Glutamine(Q) | Glutamic Acid(E) | Add charge | 6 | 4 | 8 | 2 | |
| Tyrosine(Y) | Phenylalanine(F) | Remove OH | 3 | 5 | 2 | 4 | |
| Proline(P) | Valine(V) | Block isomerization | 5 | 5 | 2 | – | |
| Deletion mutant | N Tail deletion | —— | —— | 10 | 45 | 52 | 27 |
| H2A/H2B: 68 | C Tail deletion | —— | —— | 10 | 3 | – | – |
| H3/H4: 79 | |||||||
| Comprehensive mutant | Multiple Tail Lysines(K) | Alanine(A)/Glutamine(Q)/Arginine(R) | Mimic unmodified/acetyl/deacetyl | 3 | 3 | 3 | 3 |
| H2A/H2B: 8 | Compound substitutions | —— | Mimic WT Hta1p/Htb1p | 1 | 1 | – | – |
| H3/H4: 6 | |||||||
| Total | 265 | 327 | 330 | 232 | |||
| H2A/H2B: 592 | |||||||
| H3/H4: 562 |
Bold font indicates new mutagenesis strategies, which were not included in the previous histone H3/H4 library (Dai et al. 2008).