6xwt
From Proteopedia
drosophila melanogaster CENP-A/H4 bound to N-terminal CAL1 fragment
Structural highlights
Function[CID_DROME] Histone H3-like variant which exclusively replaces conventional H3 in the nucleosome core of centromeric chromatin at the inner plate of the kinetochore (PubMed:11483958, PubMed:16839185). Required for recruitment and assembly of kinetochore proteins, mitotic progression and chromosome segregation (PubMed:24703848, PubMed:11483958, PubMed:16839185). May serve as an epigenetic mark that propagates centromere identity through replication and cell division (PubMed:11483958, PubMed:16839185).[1] [2] [3] [A0A0B4KFZ9_DROME] 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.[RuleBase:RU000528][SAAS:SAAS00581158] Publication Abstract from PubMedCentromeres are microtubule attachment sites on chromosomes defined by the enrichment of histone variant CENP-A-containing nucleosomes. To preserve centromere identity, CENP-A must be escorted to centromeres by a CENP-A-specific chaperone for deposition. Despite this essential requirement, many eukaryotes differ in the composition of players involved in centromere maintenance, highlighting the plasticity of this process. In humans, CENP-A recognition and centromere targeting are achieved by HJURP and the Mis18 complex, respectively. Using X-ray crystallography, we here show how Drosophila CAL1, an evolutionarily distinct CENP-A histone chaperone, binds both CENP-A and the centromere receptor CENP-C without the requirement for the Mis18 complex. While an N-terminal CAL1 fragment wraps around CENP-A/H4 through multiple physical contacts, a C-terminal CAL1 fragment directly binds a CENP-C cupin domain dimer. Although divergent at the primary structure level, CAL1 thus binds CENP-A/H4 using evolutionarily conserved and adaptive structural principles. The CAL1 binding site on CENP-C is strategically positioned near the cupin dimerisation interface, restricting binding to just one CAL1 molecule per CENP-C dimer. Overall, by demonstrating how CAL1 binds CENP-A/H4 and CENP-C, we provide key insights into the minimalistic principles underlying centromere maintenance. Structural basis for centromere maintenance by Drosophila CENP-A chaperone CAL1.,Medina-Pritchard B, Lazou V, Zou J, Byron O, Abad MA, Rappsilber J, Heun P, Jeyaprakash AA EMBO J. 2020 Mar 5:e103234. doi: 10.15252/embj.2019103234. PMID:32134144[4] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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Categories: Drome | Large Structures | Abad, M A | Byron, O | Heun, P | Jeyaprakash, A A | Lazou, V | Medina-Pritchard, B | Rappsilber, J | Zou, J | Cell cycle | Cell division | Centromere | Kinetochore
