PDBsum entry 1h4x

Cell differentiation

PDB id: 1h4x

Contents

Protein chains

111 a.a. *

Ligands

TRS ×2

Waters ×426

* Residue conservation analysis

PDB id:

1h4x

Name:

Cell differentiation

Title:

Structure of the bacillus cell fate determinant spoiiaa in the phosphorylated form

Structure:

Anti-sigma f factor antagonist. Chain: a, b. Synonym: spoiiaa. Engineered: yes

Source:

Bacillus sphaericus. Organism_taxid: 1421. Strain: atcc14577. Expressed in: escherichia coli. Expression_system_taxid: 562.

Resolution:

1.16Å R-factor: 0.133 R-free: 0.164

Authors:

P.R.Seavers,R.J.Lewis,J.A.Brannigan,K.H.G.Verschueren,G.N.Murshudov, A.J.Wilkinson

Key ref:

P.R.Seavers et al. (2001). Structure of the Bacillus cell fate determinant SpoIIAA in phosphorylated and unphosphorylated forms. Structure, 9, 605-614. PubMed id: 11470435 DOI: 10.1016/S0969-2126(01)00623-2

Date:

15-May-01 Release date: 06-Jul-01

Protein chains

O32723  (SP2AA_LYSSH) -  Anti-sigma F factor antagonist from Lysinibacillus sphaericus

Seq: 117 a.a.

Struc: 111 a.a.*

* PDB and UniProt seqs differ at 6 residue positions (black crosses)

DOI no: 10.1016/S0969-2126(01)00623-2

Structure 9:605-614 (2001)

PubMed id: 11470435

Structure of the Bacillus cell fate determinant SpoIIAA in phosphorylated and unphosphorylated forms.

P.R.Seavers, R.J.Lewis, J.A.Brannigan, K.H.Verschueren, G.N.Murshudov, A.J.Wilkinson.

ABSTRACT

BACKGROUND: The asymmetric cell division during sporulation in Bacillus subtilis gives rise to two compartments: the mother cell and the forespore. Each follow different programs of gene expression coordinated by a succession of alternate RNA polymerase sigma factors. The activity of the first of these sigma factors, sigmaF, is restricted to the forespore although sigmaF is present in the predivisional cell and partitions into both compartments following the asymmetric septation. For sigmaF to become active, it must escape from a complex with its cognate anti-sigma factor, SpoIIAB. This relief from SpoIIAB inhibition requires the dephosphorylation of the anti-sigma factor antagonist, SpoIIAA. The phosphorylation state of SpoIIAA is thus a key determinant of sigmaF activity and cell fate. RESULTS: We have solved the crystal structures of SpoIIAA from Bacillus sphaericus in its phosphorylated and unphosphorylated forms. The overall structure consists of a central beta-pleated sheet, one face of which is buried by a pair of alpha helices, while the other is largely exposed to solvent. The site of phosphorylation, Ser57, is located at the N terminus of helix alpha2. The phosphoserine is exceptionally well defined in the 1.2 A electron density maps, revealing that the structural changes accompanying phosphorylation are slight. CONCLUSIONS: Comparison of unphosphorylated and phosphorylated SpoIIAA shows that covalent modification has no significant effect on the global structure of the protein. The phosphoryl group has a passive role as a negatively charged flag rather than the active role it plays as a nucleus of structural reorganization in many eukaryotic signaling systems.

Selected figure(s)

Figure 2.
Figure 2. The Overall Fold of SpoIIAA(a) Ribbon tracing with the C[a] and side chain atoms of Ser57 shown in ball-and-stick.(b) Stereo C[a] trace with the N- and C-termini and every 10^th residue labeled. This and subsequent figures were drawn with the program MOLSCRIPT [49]

The above figure is reprinted by permission from Cell Press: Structure (2001, 9, 605-614) copyright 2001.

Figure was selected by an automated process.