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Structural basis of HEAT ‐kleisin interactions in the human condensin I subcomplex
Author(s) -
Hara Kodai,
Kinoshita Kazuhisa,
Migita Tomoko,
Murakami Kei,
Shimizu Kenichiro,
Takeuchi Kozo,
Hirano Tatsuya,
Hashimoto Hiroshi
Publication year - 2019
Publication title -
embo reports
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 4.584
H-Index - 184
eISSN - 1469-3178
pISSN - 1469-221X
DOI - 10.15252/embr.201847183
Subject(s) - condensin , microbiology and biotechnology , chemistry , biology , genetics , dna , cohesin , chromatin
Condensin I is a multi‐protein complex that plays an essential role in mitotic chromosome assembly and segregation in eukaryotes. It is composed of five subunits: two SMC ( SMC 2 and SMC 4), a kleisin ( CAP ‐H), and two HEAT ‐repeat ( CAP ‐D2 and CAP ‐G) subunits. Although balancing acts of the two HEAT ‐repeat subunits have been demonstrated to enable this complex to support the dynamic assembly of chromosomal axes in vertebrate cells, its underlying mechanisms remain poorly understood. Here, we report the crystal structure of a human condensin I subcomplex comprising hCAP ‐G and hCAP ‐H. hCAP ‐H binds to the concave surfaces of a harp‐shaped HEAT ‐repeat domain of hCAP ‐G. Physical interaction between hCAP ‐G and hCAP ‐H is indeed essential for mitotic chromosome assembly recapitulated in Xenopus egg cell‐free extracts. Furthermore, this study reveals that the human CAP ‐G‐H subcomplex has the ability to interact with not only double‐stranded DNA , but also single‐stranded DNA , suggesting functional divergence of the vertebrate condensin I complex in proper mitotic chromosome assembly.