PDBsum entry 3e3c

Lipid binding protein

PDB id: 3e3c

Contents

Protein chains

118 a.a.

Ligands

HHG ×2

Waters ×264

PDB id:

3e3c

Name:

Lipid binding protein

Title:

Structure of grlr-lipid complex

Structure:

L0044. Chain: a, b. Engineered: yes

Source:

Escherichia coli. Organism_taxid: 562. Strain: o157:h7. Gene: ecs4578. Expressed in: escherichia coli. Expression_system_taxid: 562.

Resolution:

2.50Å R-factor: 0.231 R-free: 0.278

Authors:

C.Jobichen,J.Sivaraman

Key ref:

C.Jobichen et al. (2009). Identification and characterization of the lipid-binding property of GrlR, a locus of enterocyte effacement regulator. Biochem J, 420, 191-199. PubMed id: 19228114

Date:

07-Aug-08 Release date: 07-Apr-09

Protein chains

Q7DB61  (Q7DB61_ECO57) -  GrlR from Escherichia coli O157:H7

Seq: 123 a.a.

Struc: 118 a.a.

Biochem J 420:191-199 (2009)

PubMed id: 19228114

Identification and characterization of the lipid-binding property of GrlR, a locus of enterocyte effacement regulator.

C.Jobichen, A.Z.Fernandis, A.Velazquez-Campoy, K.Y.Leung, Y.K.Mok, M.R.Wenk, J.Sivaraman.

ABSTRACT

Lipocalins are a broad family of proteins identified initially in eukaryotes and more recently in Gram-negative bacteria. The functions of lipocalin or lipid-binding proteins are often elusive and very diverse. Recently, we have determined the structure of GrlR (global regulator of LEE repressor), which plays a key role in the regulation of LEE (locus of enterocyte effacement) proteins. GrlR adopts a lipocalin-like fold that is composed of an eight-stranded beta-barrel followed by an alpha-helix at the C-terminus. GrlR has a highly hydrophobic cavity region and could be a potential transporter of lipophilic molecules. To verify this hypothesis, we carried out structure-based analysis of GrlR, determined the structure of the lipid-GrlR complex and measured the binding of lipid to recombinant GrlR by ITC (isothermal titration calorimetry). In addition, we identified phosphatidylglycerol and phosphatidylethanolamine as the endogenously bound lipid species of GrlR using electrospray-ionization MS. Furthermore, we have shown that the lipid-binding property of GrlR is similar to that of its closest lipocalin structural homologue, beta-lactoglobulin. Our studies demonstrate the hitherto unknown lipid-binding property of GrlR.