5trm
Crystal structure of human GCN5 histone acetyltransferase domainCrystal structure of human GCN5 histone acetyltransferase domain
Structural highlights
FunctionKAT2A_HUMAN Functions as a histone acetyltransferase (HAT) to promote transcriptional activation. Acetylation of histones gives a specific tag for epigenetic transcription activation. Has significant histone acetyltransferase activity with core histones, but not with nucleosome core particles. Also acetylates non-histone proteins, such as CEBPB (PubMed:17301242). Component of the ATAC complex, a complex with histone acetyltransferase activity on histones H3 and H4. In case of HIV-1 infection, it is recruited by the viral protein Tat. Regulates Tat's transactivating activity and may help inducing chromatin remodeling of proviral genes.[1] [2] Publication Abstract from PubMedHistone modifications, such as the frequently occurring lysine succinylation, are central to the regulation of chromatin-based processes. However, the mechanism and functional consequences of histone succinylation are unknown. Here we show that the alpha-ketoglutarate dehydrogenase (alpha-KGDH) complex is localized in the nucleus in human cell lines and binds to lysine acetyltransferase 2A (KAT2A, also known as GCN5) in the promoter regions of genes. We show that succinyl-coenzyme A (succinyl-CoA) binds to KAT2A. The crystal structure of the catalytic domain of KAT2A in complex with succinyl-CoA at 2.3 A resolution shows that succinyl-CoA binds to a deep cleft of KAT2A with the succinyl moiety pointing towards the end of a flexible loop 3, which adopts different structural conformations in succinyl-CoA-bound and acetyl-CoA-bound forms. Site-directed mutagenesis indicates that tyrosine 645 in this loop has an important role in the selective binding of succinyl-CoA over acetyl-CoA. KAT2A acts as a succinyltransferase and succinylates histone H3 on lysine 79, with a maximum frequency around the transcription start sites of genes. Preventing the alpha-KGDH complex from entering the nucleus, or expression of KAT2A(Tyr645Ala), reduces gene expression and inhibits tumour cell proliferation and tumour growth. These findings reveal an important mechanism of histone modification and demonstrate that local generation of succinyl-CoA by the nuclear alpha-KGDH complex coupled with the succinyltransferase activity of KAT2A is instrumental in histone succinylation, tumour cell proliferation, and tumour development. KAT2A coupled with the alpha-KGDH complex acts as a histone H3 succinyltransferase.,Wang Y, Guo YR, Liu K, Yin Z, Liu R, Xia Y, Tan L, Yang P, Lee JH, Li XJ, Hawke D, Zheng Y, Qian X, Lyu J, He J, Xing D, Tao YJ, Lu Z Nature. 2017 Dec 14;552(7684):273-277. doi: 10.1038/nature25003. Epub 2017 Dec 6. PMID:29211711[3] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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