NMR structure of lipoprotein YxeF from Bacillus subtilis reveals a calycin fold and distant homology with the lipocalin Blc from Escherichia coli.
The soluble monomeric domain of lipoprotein YxeF from the Gram positive bacterium B. subtilis was selected by the Northeast Structural Genomics Consortium (NESG) as a target of a biomedical theme project focusing on the structure determination of the soluble domains of bacterial lipoproteins. The solution NMR structure of YxeF reveals a calycin fold and distant homology with the lipocalin Blc from the Gram-negative bacterium E.coli. In particular, the characteristic β-barrel, which is open to the solvent at one end, is extremely well conserved in YxeF with respect to Blc. The identification of YxeF as the first lipocalin homologue occurring in a Gram-positive bacterium suggests that lipocalins emerged before the evolutionary divergence of Gram positive and Gram negative bacteria. Since YxeF is devoid of the α-helix that packs in all lipocalins with known structure against the β-barrel to form a second hydrophobic core, we propose to introduce a new lipocalin sub-family named 'slim lipocalins', with YxeF and the other members of Pfam family PF11631 to which YxeF belongs constituting the first representatives. The results presented here exemplify the impact of structural genomics to enhance our understanding of biology and to generate new biological hypotheses.
Department of Chemistry, State University of New York at Buffalo, Buffalo, New York, United States of America.
Yibing
Y
Wu
Marco
M
Punta
Rong
R
Xiao
Thomas B
TB
Acton
Bharathwaj
B
Sathyamoorthy
Fabian
F
Dey
Markus
M
Fischer
Arne
A
Skerra
Burkhard
B
Rost
Gaetano T
GT
Montelione
Thomas
T
Szyperski
D001412:Bacillus subtilis / Q000378:metabolism*; D001425:Bacterial Outer Membrane Proteins / Q000737:chemistry*; D001426:Bacterial Proteins / Q000737:chemistry*; D029968:Escherichia coli Proteins / Q000737:chemistry*; D054834:Lipocalins / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D040681:Structural Homology, Protein
D001425:Bacterial Outer Membrane Proteins; D001426:Bacterial Proteins; D029968:Escherichia coli Proteins; D054834:Lipocalins; C095894:blc protein, E coli