Lipid-binding proteins homologies

Figure 9 Relative accuracy of comparative models. Upper left panel, comparison of homologous structures that share 40% sequence identity. Upper right panel, conformations of ileal lipid-binding protein that satisfy the NMR restraints set equally well. Lower left panel, comparison of two independently determined X-ray structures of interleukin 1(3. Lower right panel, comparison of the X-ray and NMR structures of erabutoxin. The figure was prepared using the program MOLSCRIPT [236].

There is a second family of small lipid-binding proteins, the P2 family, which include among others cellular retinol- and fatty acid-binding proteins as well as a protein, P2, from myelin in the peripheral nervous system. However, members of this second family have ten antiparallel p strands in their barrels compared with the eight strands found in the barrels of the RBP superfamily. Members of the P2 family show no amino acid sequence homology to members of the RBP superfamily. Nevertheless, their three-dimensional structures have similar architecture and topology, being up-and-down P barrels. 

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S. Stengelin, H. Thuring, W. Kramer, Insights into the bile add transportation system The human deal lipid-binding protein-cholyltaurine complex and its comparison with homologous structures, Proteins Struct., Funct. Genet. 2003, 50, 312-328. 

Lerche, M.H. and Poulsen, F.M. (1998) Solution structure of barley lipid transfer protein complexed with palmitate. Two different binding modes of palmitate in the homologous maize and barley nonspecific lipid transfer proteins. Protein Science 7, 2490-2498. 

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