PDBsum entry 4i99

DNA binding protein

PDB id: 4i99

Contents

Protein chains

323 a.a.

70 a.a.

Ligands

PO4 ×3

Waters ×91

PDB id:

4i99

Name:

DNA binding protein

Title:

Crystal structure of the smchead bound to thE C-winged helix domain of scpa

Structure:

Chromosome partition protein smc. Chain: a, b. Fragment: head domain, unp residues 2-182, 1006-1172. Engineered: yes. Putative uncharacterized protein. Chain: c, d. Fragment: c-whd, unp residues126-212. Synonym: segregation and condensation protein a. Engineered: yes

Source:

Pyrococcus furiosus. Organism_taxid: 186497. Strain: dsm 3638. Gene: pf1843, smc. Expressed in: escherichia coli. Expression_system_taxid: 562. Gene: pf1842.

Resolution:

2.30Å R-factor: 0.221 R-free: 0.236

Authors:

H.C.Shin,Y.M.Soh,B.H.Oh

Key ref:

F.Bürmann et al. (2013). An asymmetric SMC-kleisin bridge in prokaryotic condensin. Nat Struct Biol, 20, 371-379. PubMed id: 23353789 DOI: 10.1038/nsmb.2488

Date:

05-Dec-12 Release date: 30-Jan-13

Protein chains

Q8TZY2  (SMC_PYRFU) -  Chromosome partition protein Smc from Pyrococcus furiosus (strain ATCC 43587 / DSM 3638 / JCM 8422 / Vc1)

Seq: 1177 a.a.

Struc: 323 a.a.*

Protein chains

Q8TZY3  (Q8TZY3_PYRFU) -  Segregation/condensation protein A from Pyrococcus furiosus (strain ATCC 43587 / DSM 3638 / JCM 8422 / Vc1)

Seq: 212 a.a.

Struc: 70 a.a.

* PDB and UniProt seqs differ at 140 residue positions (black crosses)

DOI no: 10.1038/nsmb.2488

Nat Struct Biol 20:371-379 (2013)

PubMed id: 23353789

An asymmetric SMC-kleisin bridge in prokaryotic condensin.

F.Bürmann, H.C.Shin, J.Basquin, Y.M.Soh, V.Giménez-Oya, Y.G.Kim, B.H.Oh, S.Gruber.

ABSTRACT

Eukaryotic structural maintenance of chromosomes (SMC)-kleisin complexes form large, ring-shaped assemblies that promote accurate chromosome segregation. Their asymmetric structural core comprises SMC heterodimers that associate with both ends of a kleisin subunit. However, prokaryotic condensin Smc-ScpAB is composed of symmetric Smc homodimers associated with the kleisin ScpA in a postulated symmetrical manner. Here, we demonstrate that Smc molecules have two distinct binding sites for ScpA. The N terminus of ScpA binds the Smc coiled coil, whereas the C terminus binds the Smc ATPase domain. We show that in Bacillus subtilis cells, an Smc dimer is bridged by a single ScpAB to generate asymmetric tripartite rings analogous to eukaryotic SMC complexes. We define a molecular mechanism that ensures asymmetric assembly, and we conclude that the basic architecture of SMC-kleisin rings evolved before the emergence of eukaryotes.