Cupin: a candidate molecular structure for the Nep1-like protein family

• Published in: BMC plant biology 2008-04, Vol.8 (1), p.50-50, Article 50
• Main Authors: Cechin, Adelmo L, Sinigaglia, Marialva, Lemke, Ney, Echeverrigaray, Sérgio, Cabrera, Odalys G, Pereira, Gonçalo A G, Mombach, José C M
• Format: Article
• Language: English
• Subjects: Amino Acid Motifs; Amino Acid Sequence; Confidence Intervals; Consensus Sequence; Cysteine - chemistry; Gene expression; Genetic aspects; Glycosylation; Models, Molecular; Molecular Sequence Data; Molecular Structure; Physiological aspects; Plant diseases; Plant Proteins - chemistry; Protein Structure, Secondary; Proteins; Sequence Alignment; Sequence Analysis, Protein
• ISSN: 1471-2229; 1471-2229
• DOI: 10.1186/1471-2229-8-50

NEP1-like proteins (NLPs) are a novel family of microbial elicitors of plant necrosis. Some NLPs induce a hypersensitive-like response in dicot plants though the basis for this response remains unclear. In addition, the spatial structure and the role of these highly conserved proteins are not known. We predict a 3d-structure for the beta-rich section of the NLPs based on alignments, prediction tools and molecular dynamics. We calculated a consensus sequence from 42 NLPs proteins, predicted its secondary structure and obtained a high quality alignment of this structure and conserved residues with the two Cupin superfamily motifs. The conserved sequence GHRHDWE and several common residues, especially some conserved histidines, in NLPs match closely the two cupin motifs. Besides other common residues shared by dicot Auxin-Binding Proteins (ABPs) and NLPs, an additional conserved histidine found in all dicot ABPs was also found in all NLPs at the same position. We propose that the necrosis inducing protein class belongs to the Cupin superfamily. Based on the 3d-structure, we are proposing some possible functions for the NLPs.