1qhl

CRYSTAL STRUCTURE OF THE N-TERMINAL DOMAIN OF MUKB AT 2.2A RESOLUTION

spinqualitylabelsall models 1qhl, resolution 2.20Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 1qhl is a 1 chain structure with sequence from Escherichia coli. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 2.2Å Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function MUKB_ECOLI Plays a central role in chromosome condensation, segregation and cell cycle progression. Functions as a homodimer, which is essential for chromosome partition. Involved in negative DNA supercoiling in vivo, and by this means organizes and compacts chromosomes. May achieve or facilitate chromosome segregation by condensation of DNA from both sides of a centrally located replisome during cell division. Stimulates both DNA relaxation and to a lesser extent decatenation activity of topoisomerase IV. Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMed BACKGROUND: The 170 kDa protein MukB has been implicated in ATP-dependent chromosome partitioning during cell division in Escherichia coli. MukB shares its dimeric structure and domain architecture with the ubiquitous family of SMC (structural maintenance of chromosomes) proteins that facilitate similar functions. The N-terminal domain of MukB carries a putative Walker A nucleotide-binding region and the C-terminal domain has been shown to bind to DNA. Mutant phenotypes and a domain arrangement similar to motor proteins that move on microtubules led to the suggestion that MukB might be a motor protein acting on DNA. RESULTS: We have cloned, overexpressed and crystallized a 26 kDa protein consisting of 227 N-terminal residues of MukB from E. coli. The structure has been solved using multiple anomalous dispersion and has been refined to 2.2 A resolution. The N-terminal domain of MukB has a mixed alpha/beta fold with a central six-stranded antiparallel beta sheet. The putative nucleotide-binding loop, which is part of an unexpected helix-loop-helix motif, is exposed on the surface and no nucleotide-binding pocket could be detected. CONCLUSIONS: The N-terminal domain of MukB has no similarity to the kinesin family of motor proteins or to any other nucleotide-binding protein. Together with the finding of the exposed Walker A motif this observation supports a model in which the N- and C-terminal domains come together in the dimer of MukB to form the active site. Conserved residues on one side of the molecule delineate a region of the N-terminal domain that is likely to interact with the C-terminal domain. Crystal structure of the N-terminal domain of MukB: a protein involved in chromosome partitioning.,van den Ent F, Lockhart A, Kendrick-Jones J, Lowe J Structure. 1999 Oct 15;7(10):1181-7. PMID:10545328 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Condensin

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