Mis16 Independently Recognizes Histone H4 and the CENP-ACnp1-Specific Chaperone Scm3sp

Sojin An; Hanseong Kim; Uhn-Soo Cho

doi:10.1016/j.jmb.2015.08.022

Mis16 Independently Recognizes Histone H4 and the CENP-ACnp1-Specific Chaperone Scm3sp

J Mol Biol. 2015 Oct 9;427(20):3230-3240. doi: 10.1016/j.jmb.2015.08.022. Epub 2015 Sep 4.

Authors

Sojin An¹, Hanseong Kim¹, Uhn-Soo Cho²

Affiliations

¹ Department of Biological Chemistry, University of Michigan Medical School, 1150 West Medical Center Drive, SPC 5606, Ann Arbor, MI 48109, USA.
² Department of Biological Chemistry, University of Michigan Medical School, 1150 West Medical Center Drive, SPC 5606, Ann Arbor, MI 48109, USA. Electronic address: uhnsoo@med.umich.edu.

PMID: 26343758
DOI: 10.1016/j.jmb.2015.08.022

Abstract

CENP-A is a centromere-specific histone H3 variant that is required for kinetochore assembly and accurate chromosome segregation. For it to function properly, CENP-A must be specifically localized to centromeres. In fission yeast, Scm3sp and the Mis18 complex, composed of Mis16, Eic1, and Mis18, function as a CENP-A(Cnp1)-specific chaperone and a recruiting factor, respectively, and together ensure accurate delivery of CENP-A(Cnp1) to centromeres. Although how Scm3sp specifically recognizes CENP-A(Cnp1) has been revealed recently, the recruiting mechanism of CENP-A(Cnp1) via the Mis18 complex remains unknown. In this study, we have determined crystal structures of Schizosaccharomyces japonicus Mis16 alone and in complex with the helix 1 of histone H4 (H4α1). Crystal structures followed by mutant analysis and affinity pull-downs have revealed that Mis16 recognizes both H4α1 and Scm3sp independently within the CENP-A(Cnp1)/H4:Scm3sp complex. This observation suggests that Mis16 gains CENP-A(Cnp1) specificity by recognizing both Scm3sp and histone H4. Our studies provide insights into the molecular mechanisms underlying specific recruitment of CENP-A(Cnp1)/H4:Scm3sp into centromeres.

Keywords: Dual recognition; Histone chaperone; Kinetochore; The Mis18 complex; X-ray crystallography.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Autoantigens / metabolism*
Carrier Proteins / ultrastructure*
Centromere / metabolism
Centromere Protein A
Chromosomal Proteins, Non-Histone / metabolism*
Crystallography, X-Ray
Histones / metabolism*
Molecular Chaperones / genetics
Molecular Chaperones / metabolism
Protein Structure, Tertiary
Schizosaccharomyces

Substances

Autoantigens
Carrier Proteins
Centromere Protein A
Chromosomal Proteins, Non-Histone
Histones
Molecular Chaperones

Associated data

PDB/4XYH
PDB/4XYI