Crystal structures of the free and sterol-bound forms of beta-cinnamomin
Rodrigues, M.L., Archer, M., Martel, P., Miranda, S., Thomaz, M., Enguita, F.J., Baptista, R.P., Melo, E.P., Sousa, N., Cravador, A., Carrondo, M.A.(2006) Biochim Biophys Acta 1764: 110-121
- PubMed: 16249127 
- DOI: https://doi.org/10.1016/j.bbapap.2005.09.008
- Primary Citation of Related Structures:  
2A8F, 2AIB - PubMed Abstract: 
The crystal structure of the elicitin beta-cinnamomin (beta-CIN) was determined in complex with ergosterol at 1.1 A resolution. beta-CIN/ergosterol complex crystallized in the monoclinic space group P2(1), with unit cell parameters of a = 31.0, b = 62.8, c = 50.0 A and beta = 93.4 degrees and two molecules in the asymmetric unit. Ligand extraction with chloroform followed by crystallographic analysis yielded a 1.35 A structure of beta-CIN (P4(3)2(1)2 space group) where the characteristic elicitin fold was kept. After incubation with cholesterol, a new complex structure was obtained, showing that the protein retains, after the extraction procedure, its ability to complex sterols. The necrotic effect of beta-CIN on tobacco was also shown to remain unchanged. Theoretical docking studies of the triterpene lupeol to beta-CIN provided an explanation for the apparent inability of beta-CIN to bind this ligand, as observed experimentally.
Organizational Affiliation: 
Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa, ITQB-UNL, Av. República, Apt. 127, 2781-901 Oeiras, Portugal.