title: Structural delineation of histone post-translation modifications in histone-nucleosome assembly protein complex.
abstract: Nucleosome assembly proteins (Nap) are histone chaperones with vital roles in chromatin assembly and disassembly. Decoding of histone post-translational modifications by histone chaperones is central in regulation of gene expression. We probed binding interfaces in Nap-histone complexes using histone peptide interaction arrays and chemical shift perturbation techniques. Phosphorylation at H3T32 and H3T118 enhanced Nap-peptide interactions while post-translational modifications like H3K122, H4K59 and H2AK36 diminished it. Nap recognition regions in histones H2A, H2B, H3 and H4 lie in core regions of the histone octamer, and form a surface exposed contiguous patch. Nap binding sites on H2A-H2B and H3-H4 fall on opposite surfaces of histone octamer, and the latter can therefore accommodate two dimeric Nap molecules simultaneously. Interfacial residues between Nap and histone octamer overlap with route of wrapped DNA on histone octamer, implying non-concurrent residency on the octamer by either Nap or DNA. Using NMR, we mapped Nap residues that undergo chemical shift perturbations in presence of histone peptides. Taken together, we provide an architectural model of a Nap-octamer complex which likely forms during chromatin reorganisation.
authors: Structural and Computational Biology Group, International Centre for Genetic Engineering and Biotechnology (ICGEB), Aruna Asaf Ali Road, New Delhi 110067, India.
authors: Anuj
authors: A
authors: Kumar
authors: Maruthi
authors: M
authors: Kashyap
authors: Neel Sarovar
authors: NS
authors: Bhavesh
authors: Manickam
authors: M
authors: Yogavel
authors: Amit
authors: A
authors: Sharma
mesh_terms: D000595:Amino Acid Sequence; D006657:Histones / Q000737:chemistry*; D006801:Humans; D008958:Models, Molecular; D008969:Molecular Sequence Data; D019906:Nuclear Magnetic Resonance, Biomolecular; D009690:Nucleic Acid Conformation; D009707:Nucleosomes / Q000737:chemistry*; D010446:Peptide Fragments / Q000737:chemistry; D010963:Plasmodium falciparum / Q000166:cytology; D040081:Protein Array Analysis; D054730:Protein Interaction Domains and Motifs; D025941:Protein Interaction Mapping; D055503:Protein Multimerization; D011499:Protein Processing, Post-Translational; D020836:Protein Structure, Quaternary; D015800:Protozoan Proteins / Q000737:chemistry; D017186:Titrimetry
chemical_list: D006657:Histones; D009707:Nucleosomes; D010446:Peptide Fragments; D015800:Protozoan Proteins