PDBsum entry 2d45

Transcription/DNA

PDB id: 2d45

Contents

Protein chains

117 a.a. *

DNA/RNA

Waters ×80

* Residue conservation analysis

PDB id:

2d45

Name:

Transcription/DNA

Title:

Crystal structure of the meci-meca repressor-operator complex

Structure:

5'-d(p Tp Ap Cp Tp Ap Cp Ap Tp Ap Tp Gp Tp Ap Gp Tp A)-3'. Chain: e, f, g, h. Engineered: yes. Methicillin resistance regulatory protein meci. Chain: a, b, c, d. Engineered: yes

Source:

Synthetic: yes. Staphylococcus aureus. Organism_taxid: 1280. Gene: meci. Expressed in: escherichia coli. Expression_system_taxid: 562.

Biol. unit:

Tetramer (from PQS)

Resolution:

3.80Å R-factor: 0.264 R-free: 0.297

Authors:

M.K.Safo,T.-P.Ko,F.N.Musayev,Q.Zhao,A.H.-J.Wang,G.L.Archer

Key ref:

M.K.Safo et al. (2006). Structure of the MecI repressor from Staphylococcus aureus in complex with the cognate DNA operator of mec. Acta Crystallogr Sect F Struct Biol Cryst Commun, 62, 320-324. PubMed id: 16582476 DOI: 10.1107/S1744309106009742

Date:

09-Oct-05 Release date: 25-Oct-05

Protein chains

P68261  (MECI_STAAN) -  Methicillin resistance regulatory protein MecI from Staphylococcus aureus (strain N315)

Seq: 123 a.a.

Struc: 117 a.a.

DNA/RNA chains

T-A-C-T-A-C-A-T-A-T-G-T-A-G-T-A 16 bases

T-A-C-T-A-C-A-T-A-T-G-T-A-G-T-A 16 bases

T-A-C-T-A-C-A-T-A-T-G-T-A 13 bases

A-C-A-T-A-T-G-T-A-G-T-A 12 bases

DOI no: 10.1107/S1744309106009742

Acta Crystallogr Sect F Struct Biol Cryst Commun 62:320-324 (2006)

PubMed id: 16582476

Structure of the MecI repressor from Staphylococcus aureus in complex with the cognate DNA operator of mec.

M.K.Safo, T.P.Ko, F.N.Musayev, Q.Zhao, A.H.Wang, G.L.Archer.

ABSTRACT

The dimeric repressor MecI regulates the mecA gene that encodes the penicillin-binding protein PBP-2a in methicillin-resistant Staphylococcus aureus (MRSA). MecI is similar to BlaI, the repressor for the blaZ gene of beta-lactamase. MecI and BlaI can bind to both operator DNA sequences. The crystal structure of MecI in complex with the 32 base-pair cognate DNA of mec was determined to 3.8 A resolution. MecI is a homodimer and each monomer consists of a compact N-terminal winged-helix domain, which binds to DNA, and a loosely packed C-terminal helical domain, which intertwines with its counter-monomer. The crystal contains horizontal layers of virtual DNA double helices extending in three directions, which are separated by perpendicular DNA segments. Each DNA segment is bound to two MecI dimers. Similar to the BlaI-mec complex, but unlike the MecI-bla complex, the MecI repressors bind to both sides of the mec DNA dyad that contains four conserved sequences of TACA/TGTA. The results confirm the up-and-down binding to the mec operator, which may account for cooperative effect of the repressor.

Selected figure(s)

Figure 1.
Overall structures of the MecI --mec complex. (a) The horizontal 32 bp DNA fragment of the mec operator with two dimeric MecI repressors bound. The DNA molecule is shown as sticks and the protein as ribbons, with [alpha]-helices and [beta]-strands labeled in the 'up' and 'down' dimers, respectively. (b) The vertical 24 bp DNA fragment with unpaired 3[prime prime or minute]-ends, also bound to two repressors. (c) The virtual double helix formed by the horizontal DNA fragments via lattice translations of the trigonal crystal. Acta Crystallogr Sect F Struct Biol Cryst Commun. 2006 April 1; 62(Pt 4): 320–324. Published online 2006 March 25. doi: 10.1107/S1744309106009742. Copyright [copyright] International Union of Crystallography 2006

Figure 2.
Packing of the MecI --mec and BlaI --mec crystals. (a) Unit-cell content of the trigonal MecI --mec crystal viewed along the [110] direction. (b) Another view by 90[deg] rotation about the c axis. Some molecules are removed and additional symmetry-related molecules are included to show the virtual double strands formed by the horizontal DNA segments. (c) BlaI --mec complexes in the tetragonal crystal (PDB code 1xsd). Acta Crystallogr Sect F Struct Biol Cryst Commun. 2006 April 1; 62(Pt 4): 320–324. Published online 2006 March 25. doi: 10.1107/S1744309106009742. Copyright [copyright] International Union of Crystallography 2006

The above figures are reprinted from an Open Access publication published by the IUCr: Acta Crystallogr Sect F Struct Biol Cryst Commun (2006, 62, 320-324) copyright 2006.