5e5b
From Proteopedia
Crystal structure of Human Spt16 N-terminal domain
Structural highlights
Function[SP16H_HUMAN] Component of the FACT complex, a general chromatin factor that acts to reorganize nucleosomes. The FACT complex is involved in multiple processes that require DNA as a template such as mRNA elongation, DNA replication and DNA repair. During transcription elongation the FACT complex acts as a histone chaperone that both destabilizes and restores nucleosomal structure. It facilitates the passage of RNA polymerase II and transcription by promoting the dissociation of one histone H2A-H2B dimer from the nucleosome, then subsequently promotes the reestablishment of the nucleosome following the passage of RNA polymerase II. The FACT complex is probably also involved in phosphorylation of 'Ser-392' of p53/TP53 via its association with CK2 (casein kinase II).[1] [2] [3] [4] [5] [6] Publication Abstract from PubMedThe histone chaperone FACT plays an important role in facilitating nucleosome assembly and disassembly during transcription. FACT is a heterodimeric complex consisting of Spt16 and SSRP1. The N-terminal domain of Spt16 resembles an inactive aminopeptidase. How this domain contributes to the histone chaperone activity of FACT remains elusive. Here, the crystal structure of the N-terminal domain (NTD) of human Spt16 is reported at a resolution of 1.84 A. The structure adopts an aminopeptidase-like fold similar to those of the Saccharomyces cerevisiae and Schizosaccharomyces pombe Spt16 NTDs. Isothermal titration calorimetry analyses show that human Spt16 NTD binds histones H3/H4 with low-micromolar affinity, suggesting that Spt16 NTD may contribute to histone binding in the FACT complex. Surface-residue conservation and electrostatic analysis reveal a conserved acidic patch that may be involved in histone binding. Structure of the human histone chaperone FACT Spt16 N-terminal domain.,Marciano G, Huang DT Acta Crystallogr F Struct Biol Commun. 2016 Feb;72(Pt 2):121-8. doi:, 10.1107/S2053230X15024565. Epub 2016 Jan 22. PMID:26841762[7] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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