5a24

Crystal structure of Dionain-1, the major endopeptidase in the Venus flytrap digestive juiceCrystal structure of Dionain-1, the major endopeptidase in the Venus flytrap digestive juice

Structural highlights 5a24 is a 1 chain structure with sequence from Dionaea muscipula. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 1.5Å Ligands: , Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function A0A0E3GLN3_DIOMU Publication Abstract from PubMed Carnivorous plants primarily use aspartic proteases during digestion of captured prey. In contrast, the major endopeptidases in the digestive fluid of the Venus flytrap (Dionaea muscipula) are cysteine proteases (dionain-1 to -4). Here, we present the crystal structure of mature dionain-1 in covalent complex with inhibitor E-64 at 1.5 A resolution. The enzyme exhibits an overall protein fold reminiscent of other plant cysteine proteases. The inactive glycosylated pro-form undergoes autoprocessing and self-activation, optimally at the physiologically relevant pH value of 3.6, at which the protective effect of the pro-domain is lost. The mature enzyme was able to efficiently degrade a Drosophila fly protein extract at pH 4 showing high activity against the abundant Lys- and Arg-rich protein, myosin. The substrate specificity of dionain-1 was largely similar to that of papain with preference for hydrophobic and aliphatic residues in subsite S2 and for positively charged residues in S1. A tentative structure of the pro-domain was obtained by homology modeling and suggested that a pro-peptide Lys residue intrudes the S2 pocket which is more spacious than in papain. This study provides the first analysis of a cysteine protease from the digestive fluid of a carnivorous plant and confirms the close relationship between carnivorous action and plant defense mechanisms. Enzymatic and structural characterization of the major endopeptidase in the Venus flytrap digestion fluid.,Risor MW, Thomsen LR, Sanggaard KW, Nielsen TA, Thogersen IB, Lukassen MV, Rossen L, Garcia-Ferrer I, Guevara T, Scavenius C, Meinjohanns E, Gomis-Ruth FX, Enghild JJ J Biol Chem. 2015 Dec 1. pii: jbc.M115.672550. PMID:26627834 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

spinqualitylabelsall models 5a24, resolution 1.50Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image