PDBsum entry: 2nzh

Chaperone

PDB id: 2nzh

Contents

Protein chains

110 a.a. *

Ligands

GOL

Waters ×117

* Residue conservation analysis

PDB id:

2nzh

Name:

Chaperone

Title:

Crystal structure of a secretion chaperone csaa from bacillu in the space group p 4 21 2

Structure:

Protein csaa. Chain: a, b. Synonym: secretion chaperone csaa. Engineered: yes

Source:

Bacillus subtilis. Organism_taxid: 1423. Gene: csaa, bsu19040. Expressed in: escherichia coli bl21(de3). Expression_system_taxid: 469008.

Resolution:

1.90Å R-factor: 0.202 R-free: 0.245

Authors:

Y.A.Shapova,M.Paetzel

Key ref:

Y.A.Shapova and M.Paetzel (2007). Crystallographic analysis of Bacillus subtilis CsaA. Acta Crystallogr D Biol Crystallogr, 63, 478-485. PubMed id: 17372352 DOI: 10.1107/S0907444907005045

Date:

23-Nov-06 Release date: 27-Mar-07

Protein chains

P37584  (CSAA_BACSU) -  Protein CsaA

Seq: 110 a.a.

Struc: 110 a.a.

 Gene Ontology (GO) functional annotation 

• Cellular component: cytoplasm (1 term)
• Biological process: transport (3 terms)
• Biochemical function: RNA binding (2 terms)

DOI no: 10.1107/S0907444907005045

Acta Crystallogr D Biol Crystallogr 63:478-485 (2007)

PubMed id: 17372352

Crystallographic analysis of Bacillus subtilis CsaA.

Y.A.Shapova, M.Paetzel.

ABSTRACT

Bacillus subtilis CsaA (BsCsaA) has been proposed to act as a protein-secretion chaperone in the Sec-dependent translocation pathway, possibly compensating for the lack of SecB in the Gram-positive eubacterium Bacillus subtilis. This paper presents the cloning, purification, crystallization and structures of BsCsaA in two space groups (P42(1)2 and P3(2)21) solved and refined to resolutions of 1.9 and 2.0 A, respectively. These structures complement the previously available crystal structure of CsaA from the Gram-negative eubacterium Thermus thermophilus (TtCsaA) and provide a direct structural basis for the interpretation of previously available biochemical data on BsCsaA. The sequence and structure of the proposed substrate-binding pocket are analyzed and discussed. A comparison with the TtCsaA structure reveals a different pattern of electrostatic potential in the vicinity of the binding site, which overlaps with a region of high sequence variability. In addition, the dimerization interface of this homodimeric protein is analyzed and discussed.

Selected figure(s)

Figure 2.
Figure 2 (a) A cartoon diagram of BsCsaA. Chains A and B are shown in orange and purple, respectively. (b) A C trace of the six superimposed chains from the two structures of BsCsaA, colored by B factor. Areas with the lowest B factor are colored blue and areas with the highest B factor are colored red. (c) A fragment of the 2F[o] - F[c] electron density at 1.0 , demonstrating dimerization interactions via the side-chain OH of Tyr54 hydrogen bonding to the side chain of Asp100'. (d) A C trace of the dimeric structures of BsCsaA (blue) and TtCsaA (red). Regions that show different conformations in different chains are labeled.

The above figure is reprinted by permission from the IUCr: Acta Crystallogr D Biol Crystallogr (2007, 63, 478-485) copyright 2007.

Figure was selected by an automated process.