InterPro : IPR002446

Name  Lipocalin, bacterial Short Name  Lipocalin_bac
Type  Family Description  The lipocalins are a diverse, interesting, yet poorly understood family of proteins composed, in the main, of extracellular ligand-binding proteinsdisplaying high specificity for small hydrophobic molecules [, , ]. Functionsof these proteins include transport of nutrients, control of cell regulation, pheromone transport, cryptic colouration, and the enzymatic synthesisof prostaglandins.The crystal structures of several lipocalins have been solved and show a novel 8-stranded anti-parallel beta-barrel fold well conserved within thefamily. Sequence similarity within the family is at a much lower level andwould seem to be restricted to conserved disulphides and 3 motifs, whichform a juxtaposed cluster that may act as a common cell surface receptorsite []. By contrast, at the more variable end of the fold are found an internal ligand binding site and a putative surface for the formation of macromolecular complexes []. The anti-parallel beta-barrel fold is alsoexploited by the fatty acid-binding proteins (which function similarly bybinding small hydrophobic molecules), by avidin and the closely relatedmetalloprotease inhibitors, and by triabin. Similarity at the sequence level, however, is less obvious, being confined to a single short N-terminal motif.The lipocalin family can be subdivided into kernal and outlier sets. Thekernal lipocalins form the largest self consistent group. The outlier lipocalins form several smaller distinct subgroups: the OBPs, the von Ebner's gland proteins, alpha-1-acid glycoproteins, tick histamine binding proteins and the nitrophorins.Relatively recently, bacterial lipocalins have been described for the first time [, , ]. These are lipoproteins anchored to the outer membrane of Gram-negative bacteria and some plants. Their promoters are activated at the transition between exponential and stationary growth phases. Bacteriallipocalin sequences are quite closely related to apolipoprotein D and mayserve a starvation response function in bacteria. Overexpression, membranefractionation, and metabolic labelling with tritiated palmitate showed bacterial lipocalins to be globomycin-sensitive outer membrane proteins.The bacterial lipocalins have been found in a small number of species, raising the possibility that they originated by horizontal transfer. Estimates of the G+C content in the first and third codon positions of these genes have been calculated. A biased %G+C in the 1st and 3rd codonpositions would suggest horizontal transfer. None of the computed G+C contents of the bacterial lipocalin genes were outside of the expected limits (between the first and third quartiles). These data provide no support for a hypothesis in which bacterial lipocalins were recently acquired through horizontal transfer. Further evidence against horizontal transfer will come from finding more lipocalins in different species, thus making the gene transfer hypothesis more unlikely.

Sequence Features

GO Displayer


InterPro protein domain ID --> Contigs



0 Child Features

1 Contains

Id Name Short Name Type
IPR022272 Lipocalin family conserved site Lipocalin_CS Conserved_site

0 Found In

1 Parent Features

Id Name Short Name Type
IPR022271 Lipocalin, ApoD type Lipocalin_ApoD Family

7 Publications

First Author Title Year Journal Volume Pages
Flower DR Multiple molecular recognition properties of the lipocalin protein family. 1995 J Mol Recognit 8 185-95
Pervaiz S Homology of beta-lactoglobulin, serum retinol-binding protein, and protein HC. 1985 Science 228 335-7
Flower DR The lipocalin protein family: structure and function. 1996 Biochem J 318 ( Pt 1) 1-14
Bishop RE Stationary phase expression of a novel Escherichia coli outer membrane lipoprotein and its relationship with mammalian apolipoprotein D. Implications for the origin of lipocalins. 1995 J Biol Chem 270 23097-103
Flower DR The first prokaryotic lipocalins. 1995 Trends Biochem Sci 20 498-9
Barker A VlpA of Vibrio cholerae O1: the first bacterial member of the alpha 2-microglobulin lipocalin superfamily. 1997 Microbiology 143 ( Pt 6) 1805-13
Bishop RE The bacterial lipocalins. 2000 Biochim Biophys Acta 1482 73-83

To cite PlanMine, please refer to the following publication:

Rozanski, A., Moon, H., Brandl, H., Martín-Durán, J. M., Grohme, M., Hüttner, K., Bartscherer, K., Henry, I., & Rink, J. C.
PlanMine 3.0—improvements to a mineable resource of flatworm biology and biodiversity
Nucleic Acids Research, gky1070. doi:10.1093/nar/gky1070 (2018)