Table 2. Dissociation constants (Kd) of ESCRT-0 UBDs binding to monoUb or polyUb as obtained from SPR experiments.
| Kd for Ub (μM) | |||||||
|---|---|---|---|---|---|---|---|
| STAM1–VHS wild type | 220±3.2 | ||||||
| STAM1–VHS W26A mutant | NB | ||||||
| G27E | 400±29 | ||||||
| L30D | NB | ||||||
| D31Q | 350±36 | ||||||
| S74K | 220±18 | ||||||
| N75A | 280±32 | ||||||
| G70E/A71S | 220±12 | ||||||
| Sc Hse1–VHS | 190±28 | ||||||
| Hrs–VHS | 1400±68 | ||||||
| Sc Vps27–VHS | 1500±56 | ||||||
| GGA1–VHS | NB | ||||||
| GGA2–VHS | NB | ||||||
| GGA3–VHS | 2100±53 | ||||||
| Sc GGA1–VHS | 450±8.0 | ||||||
| TOM1–VHS | 440±16 | ||||||
| TOM1L1–VHS | 950±40 | ||||||
| STAM1–UIM | 430±22 | ||||||
| Sc Vps27–UIM1 | 600±17 | ||||||
| Sc Vps27–UIM1 (A266Q/S270D) | NB | ||||||
| Sc Vps27–UIM2 | 360±4 | ||||||
| Sc Hse1–UIM | 490±5 | ||||||
| Sc Hse1–UIM (A170Q/S174D) | NB | ||||||
| Kd for: (μM) | MonoUb | K63-Ub2 | K48-Ub2 | NC-Ub2 | K63-Ub4 | K48-Ub4 | NC-Ub4 |
| Full ESCRT-0 | 920±90.5 | 110±2.8 | 370±52 | 350±23 | 18±2.3 | 43±2.2 | 140±11 |
| STAM VHS | 220±3.2 | 110±7.8 | 380±71 | 100±9.1 | 33±3.7 | 76±4.7 | 48±4.1 |
| STAM VHS–UIM | 320±5.0 | 76±7.3 | 310±16 | 90±11 | 17±3.3 | 55±3.8 | 80±6.4 |
| Hrs DUIM | 450±50.8 | 190±9.3 | 820±53 | 180±16 | 31±3.7 | 41±2.5 | 80±5.3 |
| Hrs VHS–FYVE–DUIM | 830±52.8 | 206±13.4 | 978±50.9 | 165±7.5 | 20±2.2 | 32±1.9 | 36±5.5 |
| Vps27-tandem UIMs | 350±1.2 | 70±6.0 | 180±12 | 65±7.4 | 16±2.6 | 32±3.0 | 50±9.1 |
| NB, no binding could be detected; SPR, surface plasmon resonance; Ub, ubiquitin; UBD, ubiquitin-binding domain; VHS, Vps27, Hrs, and STAM. | |||||||
| These data are the averages of three independent experiments. Values are shown to two significant figures. | |||||||