Structural basis for recognition of centromere histone variant CenH3 by the chaperone Scm3

• Published in: Nature (London) 2011-04, Vol.472 (7342), p.234-237
• Main Authors: Zhou, Zheng, Feng, Hanqiao, Zhou, Bing-Rui, Ghirlando, Rodolfo, Hu, Kaifeng, Zwolak, Adam, Miller Jenkins, Lisa M., Xiao, Hua, Tjandra, Nico, Wu, Carl, Bai, Yawen
• Format: Article
• Language: English
• Subjects: 631/337/100/2286; 631/337/103/90; 631/45/470/1981; 631/45/535; Amino Acid Motifs; Amino Acid Sequence; Autoantigens - chemistry; Autoantigens - metabolism; Binding Sites; Biological and medical sciences; Centromere - chemistry; Centromere - metabolism; Centromere Protein A; Centromeres; Chromosomal Proteins, Non-Histone - chemistry; Chromosomal Proteins, Non-Histone - metabolism; Chromosomes; Conserved Sequence; Deoxyribonucleic acid; DNA; DNA - chemistry; DNA - metabolism; DNA-Binding Proteins - chemistry; DNA-Binding Proteins - metabolism; E coli; Fundamental and applied biological sciences. Psychology; Histones - chemistry; Histones - metabolism; Humanities and Social Sciences; Humans; Hydrophobic and Hydrophilic Interactions; Interactions. Associations; Intermolecular phenomena; letter; Models, Molecular; Molecular biophysics; Molecular chaperones; Molecular Chaperones - chemistry; Molecular Chaperones - metabolism; Molecular Sequence Data; multidisciplinary; Mutation; Nuclear Magnetic Resonance, Biomolecular; Nucleosomes - chemistry; Nucleosomes - metabolism; Physiological aspects; Protein Binding; Protein Conformation; Proteins; Saccharomyces cerevisiae; Saccharomyces cerevisiae - cytology; Saccharomyces cerevisiae - metabolism; Saccharomyces cerevisiae Proteins - chemistry; Saccharomyces cerevisiae Proteins - metabolism; Science; Science (multidisciplinary); Structure; Yeast; Yeasts
• ISSN: 0028-0836; 1476-4687
• DOI: 10.1038/nature09854

Histone recognition on the centromere Centromeres, regions on the chromosome that are essential for accurate chromosome segregation, contain unique chromatin that is marked by a histone H3 variant termed CenH3 or CENP-A. The simple centromeres of budding yeast provide an attractive system for investigating centromere biology, including the pathway of CenH3 deposition and the architecture of the centromeric nucleosome. The chaperone Scm3 is required in budding yeast for the deposition of CenH3 (called Cse4) at centromeres. Zhou et al . present the nuclear magnetic resonance structure of Cse4 and histone H4 complexed with Scm3, and outline the structural basis for the recognition of Cse4 by Scm3. They propose a model for Scm3 function as a chaperone that has implications for the assembly of centromeric nucleosomes. The centromere is a unique chromosomal locus that ensures accurate segregation of chromosomes during cell division by directing the assembly of a multiprotein complex, the kinetochore 1 . The centromere is marked by a conserved variant of conventional histone H3 termed CenH3 or CENP-A (ref. 2 ). A conserved motif of CenH3, the CATD, defined by loop 1 and helix 2 of the histone fold, is necessary and sufficient for specifying centromere functions of CenH3 (refs 3 , 4 ). The structural basis of this specification is of particular interest. Yeast Scm3 and human HJURP are conserved non-histone proteins that interact physically with the (CenH3–H4) 2 heterotetramer and are required for the deposition of CenH3 at centromeres in vivo 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 . Here we have elucidated the structural basis for recognition of budding yeast ( Saccharomyces cerevisiae ) CenH3 (called Cse4) by Scm3. We solved the structure of the Cse4-binding domain (CBD) of Scm3 in complex with Cse4 and H4 in a single chain model. An α-helix and an irregular loop at the conserved amino terminus and a shorter α-helix at the carboxy terminus of Scm3(CBD) wraps around the Cse4–H4 dimer. Four Cse4-specific residues in the N-terminal region of helix 2 are sufficient for specific recognition by conserved and functionally important residues in the N-terminal helix of Scm3 through formation of a hydrophobic cluster. Scm3(CBD) induces major conformational changes and sterically occludes DNA-binding sites in the structure of Cse4 and H4. These findings have implications for the assembly and architecture of the centromeric nucleosome.