Table 1.
Human BAF and PBAF components and their yeast orthologs
| BAFs | Human
|
Yeast
orthologs
|
Known domains | ||
|---|---|---|---|---|---|
| BAF | PBAF | SWI/SNF | Rsc | ||
| BAF250/p270 | + | − | SWI1 | — | ARID |
| BAF180 | − | + | — | Rsc1, 2, 4 | Bromo, BAH, HMG |
| BRG1 | + | + | SWI2 | STH1 | ATPase, bromo |
| hbrm | + | − | SWI2 | — | ATPase, bromo |
| BAF170 | + | + | SWI3 | Rsc8 | Myb, Leu-zipper |
| BAF155 | + | + | SWI3 | Rsc8 | Myb, Leu-zipper |
| BAF60a | + | + | SWP73 | Rsc6 | |
| BAF57 | + | + | — | — | HMG, coiled-coil |
| BAF53 | + | + | ARP7, 9 | ARP7, 9 | Actin-related protein |
| Actin | + | + | — | — | ATPase, Ca++ binding |
| BAF47 | + | + | SNF5 | SFH1 | |
Microsequencing was done for selected PBAF subunits. Twelve peptide sequences were obtained for the 190-kDa band: 10 are specifically from BRG1; 2 from sequences conserved between BRG1 and hbrm; and none is hbrm-specific. All 3 peptide sequences obtained for the 60-kDa band are from BAF60a, but not BAF60b or BAF60c. All 6 peptides for the 53-kDa band are from BAF53a. From the 48-kDa band, 3 peptides are from actin and 5 are from hSNF5/BAF47. BAF250 has been identified as the same protein as p270 (51), which has been independently cloned by Moran and colleagues (48, 49). They found that p270 is related to yeast SWI1 and Drosophila Osa and showed that p270 associates with several BAF subunits. Osa has been shown to be a subunit of a Drosophila SWI/SNF-related complex (50).