Tuned SMC Arms Drive Chromosomal Loading of Prokaryotic Condensin

• DOI: 10.1016/j.molcel.2017.01.026
• Publication Date: 2017-02-23T19:18:09Z
• Authors: Frank Bürmann; Alrun Basfeld; Roberto Vazquez N...; Marie-Laure Diebo...; Larissa Wilhelm; Stephan Gruber
• Keywords: Condensin

SMC proteins support vital cellular processes in all domains of life by organizing chromosomal DNA. They are composed ATPase "head" and "hinge" dimerization a connecting coiled-coil "arm." Binding to kleisin subunit creates closed tripartite ring, whose ∼47-nm-long arms act as barrier for DNA entrapment. Here, we uncover another, more active function the bacterial Smc arm. Using high-throughput genetic engineering, resized arm range 6-60 nm found that it was functional only specific length regimes following periodic pattern. Natural sequences reflect these constraints. Mutants with improper or peptide insertions efficiently target loading sites hydrolyze ATP but fail use hydrolysis relocation onto flanking We propose implement force transmission upon nucleotide mediate capture loop extrusion.