Sandbox Reserved 654: Difference between revisions
From Proteopedia
Jump to navigationJump to search
No edit summary |
|||
| Line 29: | Line 29: | ||
== '''Mechanism''' == | == '''Mechanism''' == | ||
[[Image: | [[Image:F1.medium.gif |thumb|250 px|right| Acetylation of the lysine and its effects on chromatin remodeling..]] | ||
Tat acetylation at K50 results in its dissociation from TAR RNA and promotes formation of a multiprotein complex composed of Tat, p300/CBP, and PCAF. [Benkirane et al. 1998]The bromodomains of PCAF and CBP have three major points of contact that allow for site-specific histone recognition. First, the acetylated lysine of the target protein enters a hydrophobic pocket embedded between the ZA and BC loops at the bottom of the protein. The Asn803 residue in the bromodomain forms a hydrogen bond with the amide nitrogen of the acetyl-lysine. Next, residues in the ZA and/or BC loops interact with residues adjacent to the acetyl-lysine, which reinforces the acetyl-lysine binding in the bromodomain. Finally, additional residues in the ZA and BC loops that face opposite to the bromodomain form hydrophobic and/ or electrostatic interaction with the target protein 3 residues away from the acetyl-lysine. This residue clamps on the BC loop together with the acetyl-lysine side chain that is bound inside the hydrophobic pocket of the bromodomain.[http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3339198/] | Tat acetylation at K50 results in its dissociation from TAR RNA and promotes formation of a multiprotein complex composed of Tat, p300/CBP, and PCAF. [Benkirane et al. 1998]The bromodomains of PCAF and CBP have three major points of contact that allow for site-specific histone recognition. First, the acetylated lysine of the target protein enters a hydrophobic pocket embedded between the ZA and BC loops at the bottom of the protein. The Asn803 residue in the bromodomain forms a hydrogen bond with the amide nitrogen of the acetyl-lysine. Next, residues in the ZA and/or BC loops interact with residues adjacent to the acetyl-lysine, which reinforces the acetyl-lysine binding in the bromodomain. Finally, additional residues in the ZA and BC loops that face opposite to the bromodomain form hydrophobic and/ or electrostatic interaction with the target protein 3 residues away from the acetyl-lysine. This residue clamps on the BC loop together with the acetyl-lysine side chain that is bound inside the hydrophobic pocket of the bromodomain.[http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3339198/] | ||
