6uph
From Proteopedia
Structure of a Yeast Centromeric Nucleosome at 2.7 Angstrom resolution
Structural highlights
Function[H2B1_KLULA] Core component of nucleosome. Nucleosomes wrap and compact DNA into chromatin, limiting DNA accessibility to the cellular machineries which require DNA as a template. Histones thereby play a central role in transcription regulation, DNA repair, DNA replication and chromosomal stability. DNA accessibility is regulated via a complex set of post-translational modifications of histones, also called histone code, and nucleosome remodeling. [CENPA_YEAST] Histone H3-like variant which exclusively replaces conventional H3 in the nucleosome core of centromeric chromatin at the inner plate of the kinetochore. Required for recruitment and assembly of kinetochore proteins, mitotic progression and chromosome segregation. May serve as an epigenetic mark that propagates centromere identity through replication and cell division. Required for functional chromatin architecture at the yeast 2-micron circle partitioning locus and promotes equal plasmid segregation.[1] [2] [3] [4] [5] [6] [7] [8] [9] [10] [11] [Q6CMU6_KLULA] Core component of nucleosome. Nucleosomes wrap and compact DNA into chromatin, limiting DNA accessibility to the cellular machineries which require DNA as a template. Histones thereby play a central role in transcription regulation, DNA repair, DNA replication and chromosomal stability. DNA accessibility is regulated via a complex set of post-translational modifications of histones, also called histone code, and nucleosome remodeling (By similarity).[SAAS:SAAS00202799] Publication Abstract from PubMedKinetochores mediate chromosome segregation during cell division. They assemble on centromeric nucleosomes and capture spindle microtubules. In budding yeast, a kinetochore links a single nucleosome, containing the histone variant Cse4(CENP-A) instead of H3, with a single microtubule. Conservation of most kinetochore components from yeast to metazoans suggests that the yeast kinetochore represents a module of the more complex metazoan arrangements. We describe here a streamlined protocol for reconstituting a yeast centromeric nucleosome and a systematic exploration of cryo-grid preparation. These developments allowed us to obtain a high-resolution cryoelectron microscopy reconstruction. As suggested by previous work, fewer base pairs are in tight association with the histone octamer than there are in canonical nucleosomes. Weak binding of the end DNA sequences may contribute to specific recognition by other inner kinetochore components. The centromeric nucleosome structure and the strategies we describe will facilitate studies of many other aspects of kinetochore assembly and chromatin biochemistry. Cryoelectron Microscopy Structure of a Yeast Centromeric Nucleosome at 2.7 A Resolution.,Migl D, Kschonsak M, Arthur CP, Khin Y, Harrison SC, Ciferri C, Dimitrova YN Structure. 2020 Jan 29. pii: S0969-2126(19)30440-X. doi:, 10.1016/j.str.2019.12.002. PMID:32004465[12] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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Categories: Baker's yeast | Candida sphaerica | Large Structures | Arthur, C P | Ciferri, C | Dimitrova, Y N | Harrison, S C | Khin, Y | Kschonsak, M | Migl, D | Cell cycle | Centromere | Histone | Kinetochore | Nucleosome | Yeast
