Structure of the human histone chaperone FACT Spt16 N-terminal domain
- Publisher: Wiley
Acta Crystallographica. Section F, Structural Biology Communications
FACT | histones | Spt16 | aminopeptidase | pita-bread fold | histone chaperone | Research Communications
mesheuropmc: congenital, hereditary, and neonatal diseases and abnormalities
The histone chaperone FACT plays an important role in facilitating nucleosome\ud assembly and disassembly during transcription. FACT is a heterodimeric\ud complex consisting of Spt16 and SSRP1. The N-terminal domain of Spt16\ud resembles an inactive aminopeptidase. How this domain contributes to the\ud histone chaperone activity of FACT remains elusive. Here, the crystal structure\ud of the N-terminal domain (NTD) of human Spt16 is reported at a resolution\ud of 1.84 A˚ . The structure adopts an aminopeptidase-like fold similar to those\ud of the Saccharomyces cerevisiae and Schizosaccharomyces pombe Spt16 NTDs.\ud Isothermal titration calorimetry analyses show that human Spt16 NTD binds\ud histones H3/H4 with low-micromolar affinity, suggesting that Spt16 NTD may\ud contribute to histone binding in the FACT complex. Surface-residue conservation\ud and electrostatic analysis reveal a conserved acidic patch that may be\ud involved in histone binding.