13S condensin actively reconfigures DNA by introducing global positive writhe: implications for chromosome condensation.

Kimura, K; Rybenkov, V V; Crisona, N J; Hirano, T; Cozzarelli, N R · Cell · 1999

basic_science · Level V

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Abstract

Xenopus 13S condensin converts interphase chromatin into mitotic-like chromosomes, and, in the presence of ATP and a type I topoisomerase, introduces (+) supercoils into DNA. The specific production of (+) trefoil knots in the presence of condensin and a type II topoisomerase shows that condensin reconfigures DNA by introducing an ordered, global, (+) writhe. Knotting required ATP hydrolysis and cell cycle-specific phosphorylation of condensin. Condensin bound preferentially to (+) supercoiled DNA in the presence of ATP but not in its absence. Our results suggest a mechanism for the compaction of chromatin by condensin during mitosis.

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