Structural Studies of a Bacterial Condensin Complex Reveal ATP-Dependent Disruption of Intersubunit Interactions

Condensins are key mediators of chromosome condensation across organisms. Like other condensins, the bacterial MukBEF condensin complex consists of an SMC family protein dimer containing two ATPase head domains, MukB, and two interacting subunits, MukE and MukF. We report complete structural views of the intersubunit interactions of this condensin along with ensuing studies that reveal a role for the ATPase activity of MukB. MukE and MukF together form an elongated dimeric frame, and MukF's C-terminal winged-helix domains (C-WHDs) bind MukB heads to constitute closed ring-like structures. Surprisingly, one of the two bound C-WHDs is forced to detach upon ATP-mediated engagement of MukB heads. This detachment reaction depends on the linker segment preceding the C-WHD, and mutations on the linker restrict cell growth. Thus ATP-dependent transient disruption of the MukB-MukF interaction, which creates openings in condensin ring structures, is likely to be a critical feature of the functional mechanism of condensins.

[1]  A. Strunnikov.  SMC complexes in bacterial chromosome condensation and segregation. , 2006, Plasmid.

[2]  Z. M. Petrushenko,et al.  DNA Reshaping by MukB RIGHT-HANDED KNOTTING, LEFT-HANDED SUPERCOILING* , 2006, Journal of Biological Chemistry.

[3]  J. Swedlow,et al.  The making of the mitotic chromosome: modern insights into classical questions. , 2003, Molecular cell.

[4]  J. Berger,et al.  The MukF subunit of Escherichia coli condensin: architecture and functional relationship to kleisins , 2005, The EMBO journal.

[5]  J. Kaper,et al.  Construction of an eae deletion mutant of enteropathogenic Escherichia coli by using a positive-selection suicide vector , 1991, Infection and immunity.

[6]  T. Ogura,et al.  E.coli MukB protein involved in chromosome partition forms a homodimer with a rod‐and‐hinge structure having DNA binding and ATP/GTP binding activities. , 1992, The EMBO journal.

[7]  T. Ogura,et al.  The new gene mukB codes for a 177 kd protein with coiled‐coil domains involved in chromosome partitioning of E. coli. , 1991, The EMBO journal.

[8]  Kim Nasmyth,et al.  A Topological Interaction between Cohesin Rings and a Circular Minichromosome , 2005, Cell.

[9]  Kim Nasmyth,et al.  Structure and stability of cohesin's Smc1-kleisin interaction. , 2004, Molecular cell.

[10]  Qinhong Wang,et al.  MukEF Is Required for Stable Association of MukB with the Chromosome , 2007, Journal of bacteriology.

[11]  R. Kobayashi,et al.  Condensins, Chromosome Condensation Protein Complexes Containing XCAP-C, XCAP-E and a Xenopus Homolog of the Drosophila Barren Protein , 1997, Cell.

[12]  R. B. Jensen,et al.  Dynamic localization of proteins and DNA during a bacterial cell cycle , 2002, Nature Reviews Molecular Cell Biology.

[13]  Z. M. Petrushenko,et al.  Antagonistic Interactions of Kleisins and DNA with Bacterial Condensin MukB* , 2006, Journal of Biological Chemistry.

[14]  K. Morikawa,et al.  Comparison of MukB homodimer versus MukBEF complex molecular architectures by electron microscopy reveals a higher-order multimerization. , 2005, Biochemical and biophysical research communications.

[15]  A. Grossman,et al.  Characterization of a prokaryotic SMC protein involved in chromosome partitioning. , 1998, Genes & development.

[16]  Z. M. Petrushenko,et al.  MukB acts as a macromolecular clamp in DNA condensation , 2008, Nature Structural &Molecular Biology.

[17]  H. Erickson,et al.  The Symmetrical Structure of Structural Maintenance of Chromosomes (SMC) and MukB Proteins: Long, Antiparallel Coiled Coils, Folded at a Flexible Hinge , 1998, The Journal of cell biology.

[18]  T. Hirano,et al.  Positive and negative regulation of SMC–DNA interactions by ATP and accessory proteins , 2004, The EMBO journal.

[19]  P. Graumann,et al.  Dynamic assembly, localization and proteolysis of the Bacillus subtilis SMC complex , 2005, BMC Cell Biology.

[20]  John F Hunt,et al.  Cooperative, ATP-dependent Association of the Nucleotide Binding Cassettes during the Catalytic Cycle of ATP-binding Cassette Transporters* , 2002, The Journal of Biological Chemistry.

[21]  J. Rappsilber,et al.  Explorer Molecular and Genetic Analysis of Condensin Function in Vertebrate Cells , 2017 .

[22]  A. Strunnikov,et al.  Cell cycle‐dependent localization of two novel prokaryotic chromosome segregation and condensation proteins in Bacillus subtilis that interact with SMC protein , 2002, The EMBO journal.

[23]  T. Mitchison,et al.  A heterodimeric coiled-coil protein required for mitotic chromosome condensation in vitro , 1994, Cell.

[24]  Margarete M S Heck,et al.  The evolution of SMC proteins: phylogenetic analysis and structural implications. , 2004, Molecular biology and evolution.

[25]  T. Hirano.  At the heart of the chromosome: SMC proteins in action , 2006, Nature Reviews Molecular Cell Biology.

[26]  T. Ogura,et al.  Identification of two new genes, mukE and mukF, involved in chromosome partitioning in Escherichia coli. , 1996, Molecular & general genetics : MGG.

[27]  D. Oesterhelt,et al.  Discovery of two novel families of proteins that are proposed to interact with prokaryotic SMC proteins, and characterization of the Bacillus subtilis family members ScpA and ScpB , 2002, Molecular microbiology.

[28]  R. B. Jensen,et al.  The Caulobacter crescentus smc gene is required for cell cycle progression and chromosome segregation. , 1999, Proceedings of the National Academy of Sciences of the United States of America.

[29]  H. Niki,et al.  Complex formation of MukB, MukE and MukF proteins involved in chromosome partitioning in Escherichia coli , 1999, The EMBO journal.