InterPro : IPR003057

Name  Invertebrate colouration protein Short Name  Invtbrt_color
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 []. Functions of these proteins include transport of nutrients, control of cell regulation, pheromone transport, cryptic colouration, and the enzymatic synthesis of prostaglandins. The crystal structures of several lipocalins have been solved and show a novel 8-stranded anti-parallel beta-barrel fold well conserved within the family. Sequence similarity within the family is at a much lower level and would seem to be restricted to conserved disulphides and 3 motifs, which form a juxtaposed cluster that may act as a common cell surface receptor site [, ]. 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 also exploited by the fatty acid-binding proteins, which function similarly by binding small hydrophobic molecules. Similarity at the sequence level, however, is less obvious, being confined to a single short N-terminal motif.A number of lipocalins act in invertebrate colouration and are represented in this entry. These include: bilin binding protein from the cabbage white butterfly (Pieris brassicae), the closely related protein insecticyanin from Manduca sexta(Tobacco hawkmoth) and the lobster protein crustacyanin. Like other members of the family, they bind small molecules, and gain their colourant properties from interaction with their ligands. Crustacyanin (meaning `shell blue') is the general name given to the carotenoprotein complex found in the epicuticle, or calcified outer layer,of the lobster carapace. It acts as the dominant pigment of the lobster shell, giving rise to its characteristic blue colour. In solution, crustacyanin exists as an equilibrium mixture between several distinctforms, differing in their physical and spectral properties. The native, blue form (alpha-crustacyanin), which predominates in vivo, will, at low ionic strength, form alpha'-crustacyanin; this in turn changes to purplebeta-crustacyanin on standing. The alpha to alpha' transition is favouredby low ionic strength and is reversible, while conversion into beta-crustacyanin is irreversible. Native alpha-crustacyanin is an octamer ofheterodimers, totalling 16 separate polypeptide chains, each dimer binding two molecules of astaxanthin, beta-crustacyanin corresponding to the free heterodimer.

Sequence Features

GO Displayer


InterPro protein domain ID --> Contigs



0 Child Features

4 Contains

Id Name Short Name Type
IPR000566 Lipocalin/cytosolic fatty-acid binding domain Lipocln_cytosolic_FA-bd_dom Domain
IPR011038 Calycin-like Calycin-like Domain
IPR012674 Calycin Calycin Domain
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

4 Publications

First Author Title Year Journal Volume Pages
Flower DR Mouse oncogene protein 24p3 is a member of the lipocalin protein family. 1991 Biochem Biophys Res Commun 180 69-74
Flower DR Structure and sequence relationships in the lipocalins and related proteins. 1993 Protein Sci 2 753-61
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

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)