Structures of two Arabidopsis thaliana major latex proteins represent novel helix-grip folds. Proteins 2009 Jul;76(1):237-43
Date
03/28/2009Pubmed ID
19326460Pubmed Central ID
PMC2845785DOI
10.1002/prot.22396Scopus ID
2-s2.0-66249143729 (requires institutional sign-in at Scopus site) 67 CitationsAbstract
The major latex proteins (MLP) are a protein family first identified in the latex of opium poppy. They are found only in plants and have 24 identified members in Arabidopsis alone as well as in other plants such as peach, strawberry, melon, cucumber, and soybean. While the function of the MLPs is unknown, they have been associated with fruit and flower development and in pathogen defense responses. Based on modest sequence similarity, they have been characterized as members of the Bet v 1 protein superfamily; however, no structures have yet been reported. As part of an ongoing structural genomics effort, we determined the structures of two Arabidopsis thaliana MLPs: the solution structure of MLP28 (gene product of At1g70830.1) and the crystal structure of At1g24000.1. The structures revealed distinct differences when compared to one another and to the typical Bet v 1 fold. Nevertheless, NMR titration experiments demonstrated that the characteristic Bet v 1 hydrophobic binding pocket of At1g24000.1 is able to bind a ligand, suggesting that it plays a role in the function of the MLPs. A structure-based sequence analysis identified conserved hydrophobic residues in the long alpha helix that contribute to the binding cavity and may specify preferred ligands for the MLP family.
Author List
Lytle BL, Song J, de la Cruz NB, Peterson FC, Johnson KA, Bingman CA, Phillips GN Jr, Volkman BFAuthors
Francis C. Peterson PhD Professor in the Biochemistry department at Medical College of WisconsinBrian F. Volkman PhD Professor in the Biochemistry department at Medical College of Wisconsin
MESH terms used to index this publication - Major topics in bold
Amino Acid SequenceAntigens, Plant
Arabidopsis
Arabidopsis Proteins
Ligands
Molecular Sequence Data
Nuclear Magnetic Resonance, Biomolecular
Phylogeny
Protein Binding
Protein Conformation
Protein Structure, Secondary
Sequence Alignment
Structural Homology, Protein
