title: Dimeric structure of p300/CBP associated factor.
abstract: BACKGROUND
  p300/CBP associating factor (PCAF, also known as KAT2B for lysine acetyltransferase 2B) is a catalytic subunit of megadalton metazoan complex ATAC (Ada-Two-A containing complex) for acetylation of histones. However, relatively little is known about the regulation of the enzymatic activity of PCAF.
  
  
  RESULTS
  Here we present two dimeric structures of the PCAF acetyltransferase (HAT) domain. These dimerizations are mediated by either four-helical hydrophobic interactions or a ß-sheet extension. Our chemical cross-linking experiments in combined with site-directed mutagenesis demonstrated that the PCAF HAT domain mainly forms a dimer in solution through one of the observed interfaces. The results of maltose binding protein (MBP)-pulldown, co-immunoprecipitation and multiangle static light scattering experiments further indicated that PCAF dimeric state is detectable and may possibly exist in vivo.
  
  
  CONCLUSIONS
  Taken together, our structural and biochemical studies indicate that PCAF appears to be a dimer in its functional ATAC complex.
authors.forename: Shasha
authors.initials: S
authors.lastname: Shi
authors.forename: Juanyu
authors.initials: J
authors.lastname: Lin
authors.forename: Yongfei
authors.initials: Y
authors.lastname: Cai
authors.forename: Jiao
authors.initials: J
authors.lastname: Yu
authors.forename: Haiyan
authors.initials: H
authors.lastname: Hong
authors.forename: Kunmei
authors.initials: K
authors.lastname: Ji
authors.forename: Jennifer S
authors.initials: JS
authors.lastname: Downey
authors.forename: Xiaodong
authors.initials: X
authors.lastname: Lu
authors.forename: Ruichuan
authors.initials: R
authors.lastname: Chen
authors.affiliation: State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Xiamen University, Xiamen 361102, China. jhan@xmu.edu.cn.
authors.forename: Jiahuai
authors.initials: J
authors.lastname: Han
authors.forename: Aidong
authors.initials: A
authors.lastname: Han
mesh_terms: D020134:Catalytic Domain; D006801:Humans; D008958:Models, Molecular; D016297:Mutagenesis, Site-Directed; D011487:Protein Conformation; D055503:Protein Multimerization; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D050880:p300-CBP Transcription Factors / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D000099224:p300-CBP-Associated Factor
chemical_list: D050880:p300-CBP Transcription Factors; D000099224:p300-CBP-Associated Factor