1e69

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spinqualitylabelsall models 1e69, resolution 3.1Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image

SMC HEAD DOMAIN FROM THERMOTOGA MARITIMA

Overview

SMC (structural maintenance of chromosomes) proteins are large coiled-coil, proteins involved in chromosome condensation, sister chromatid cohesion, and DNA double-strand break processing. They share a conserved five-domain, architecture with three globular domains separated by two long coiled-coil, segments. The coiled-coil segments are antiparallel, bringing the N and, C-terminal globular domains together. We have expressed a fusion protein, of the N and C-terminal globular domains of Thermotoga maritima SMC in, Escherichia coli by replacing the approximately 900 residue coiled-coil, and hinge segment with a short peptide linker. The SMC head domain (SMChd), binds and condenses DNA in an ATP-dependent manner. Using, selenomethionine-substituted protein and multiple anomalous dispersion, phasing, we have solved the crystal structure of the SMChd to 3.1 A, resolution. In the monoclinic crystal form, six SMChd molecules form two, turns of a helix. The fold of SMChd is closely related to the ATP-binding, cassette (ABC) ATPase family of proteins and Rad50, a member of the SMC, family involved in DNA double-strand break repair. In SMChd, the ABC, ATPase fold is formed by the N and C-terminal domains with the 900 residue, coiled-coil and hinge segment inserted in the middle of the fold. The, crystal structure of an SMChd confirms that the coiled-coil segments in, SMC proteins are anti-parallel and shows how the N and C-terminal domains, come together to form an ABC ATPase. Comparison to the structure of the, MukB N-terminal domain demonstrates the close relationship between MukB, and SMC proteins, and indicates a helix to strand conversion when N and, C-terminal parts come together.

About this Structure

1E69 is a Single protein structure of sequence from Thermotoga maritima. Full crystallographic information is available from OCA.

Reference

Crystal structure of the SMC head domain: an ABC ATPase with 900 residues antiparallel coiled-coil inserted., Lowe J, Cordell SC, van den Ent F, J Mol Biol. 2001 Feb 9;306(1):25-35. PMID:11178891

Page seeded by OCA on Sat Nov 24 21:49:14 2007