4EFP

Bombyx mori lipoprotein 7 isolated from its natural source at 1.33 A resolution

Summary for 4EFP

• Entry DOI: 10.2210/pdb4efp/pdb
• Related: 3PUB 4EFQ 4EFR
• Descriptor: 30kDa protein, THIOCYANATE ION, CADMIUM ION, ... (8 entities in total)
• Functional Keywords: vhs domain, beta-trefoil, unknown function
• Biological source: Bombyx mori (silk moth,silkworm)
• Total number of polymer chains: 2
• Total formula weight: 56081.92

Authors

Pietrzyk, A.J.,Panjikar, S.,Bujacz, A.,Mueller-Dieckmann, J.,Jaskolski, M.,Bujacz, G. (deposition date: 2012-03-30, release date: 2012-08-29, Last modification date: 2024-11-20)

Primary citation

Pietrzyk, A.J.,Panjikar, S.,Bujacz, A.,Mueller-Dieckmann, J.,Lochynska, M.,Jaskolski, M.,Bujacz, G.
High-resolution structure of Bombyx mori lipoprotein 7: crystallographic determination of the identity of the protein and its potential role in detoxification.
Acta Crystallogr.,Sect.D, 68:1140-1151, 2012

PubMed Abstract: Three crystal structures of a lipoprotein (Bmlp7) of unknown function, a member of the 30 kDa lipoprotein family from mulberry silkworm (Bombyx mori L.) haemolymph, have been determined. The 1.33 Å resolution structure is an excellent example of how a precise crystallographic study can contribute to protein identification. The correct sequence of this haemolymph-isolated protein was assigned thanks to superb-quality electron-density maps. Two unexpected cadmium cations were found in this crystal structure [Bmlp7-I(Cd)] and their presence may be connected to a detoxification mechanism in this insect. For a comparison of the metal-binding sites, the crystal structure of a platinum complex (Bmlp7-Pt) was also solved at 1.94 Å resolution. The third (2.50 Å resolution) structure, of the native protein harvested in a different season (Bmlp7-II), corresponds to a different polymorph with an altered pattern of intermolecular interactions and with a total absence of cadmium ions and highlights the possible involvement of Bmlp7 in the response to environmental pollution. The N-terminal domain of Bmlp7 has a fold resembling a clockwise spiral created by six helices and can be classified as a VHS domain. The C-terminal domain is folded as a β-trefoil. The biological function of Bmlp7 is unknown, but its structural homology to sugar-binding proteins suggests that, in analogy to other 30 kDa haemolymph lipoproteins, it could play a role as an anti-apoptotic factor or function in the immune response of the insect to fungal infections.

PubMed: 22948915
DOI: 10.1107/S0907444912021555

Experimental method

X-RAY DIFFRACTION (1.33 Å)