1QWD

CRYSTAL STRUCTURE OF A BACTERIAL LIPOCALIN, THE BLC GENE PRODUCT FROM E. COLI

Summary for 1QWD

• Entry DOI: 10.2210/pdb1qwd/pdb
• Descriptor: Outer membrane lipoprotein blc (2 entities in total)
• Functional Keywords: bacterial lipocalin, lipid binding protein
• Biological source: Escherichia coli
• Cellular location: Cell outer membrane; Lipid-anchor: P0A901
• Total number of polymer chains: 2
• Total formula weight: 40753.70

Authors

Campanacci, V.,Nurizzo, D.,Spinelli, S.,Valencia, C.,Cambillau, C. (deposition date: 2003-09-02, release date: 2004-04-06, Last modification date: 2024-02-14)

Primary citation

Campanacci, V.,Nurizzo, D.,Spinelli, S.,Valencia, C.,Tegoni, M.,Cambillau, C.
The crystal structure of the Escherichia coli lipocalin Blc suggests a possible role in phospholipid binding
Febs Lett., 562:183-188, 2004

PubMed Abstract: Lipocalins form a large multifunctional family of small proteins (15-25 kDa) first discovered in eukaryotes. More recently, several types of bacterial lipocalins have been reported, among which Blc from Escherichia coli is an outer membrane lipoprotein. As part of our structural genomics effort on proteins from E. coli, we have expressed, crystallized and solved the structure of Blc at 1.8 A resolution using remote SAD with xenon. The structure of Blc, the first of a bacterial lipocalin, exhibits a classical fold formed by a beta-barrel and a alpha-helix similar to that of the moth bilin binding protein. Its empty and open cavity, however, is too narrow to accommodate bilin, while the alkyl chains of two fatty acids or of a phospholipid could be readily modeled inside the cavity. Blc was reported to be expressed under stress conditions such as starvation or high osmolarity, during which the cell envelope suffers and requires maintenance. These data, together with our structural interpretation, suggest a role for Blc in storage or transport of lipids necessary for membrane repair or maintenance.

PubMed: 15044022
DOI: 10.1016/S0014-5793(04)00199-1

Experimental method

X-RAY DIFFRACTION (1.75 Å)