6ORM

Crystal Structure of Peruvianin-I (Cysteine peptidase from Thevetia peruviana latex)

Summary for 6ORM

• Entry DOI: 10.2210/pdb6orm/pdb
• Descriptor: Peruvianin-I, beta-D-mannopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose, beta-D-mannopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose-(1-4)-[alpha-L-fucopyranose-(1-3)]2-acetamido-2-deoxy-beta-D-glucopyranose, ... (5 entities in total)
• Functional Keywords: laticifer, hydrolase
• Biological source: Thevetia peruviana
• Total number of polymer chains: 3
• Total formula weight: 69084.74

Authors

Cruz, W.T.,Bezerra, E.H.S.,da Silva, F.M.S.,Freire, V.N.,Ramos, M.V.,Rocha, B.A.M.,Freitas, C.D.T. (deposition date: 2019-04-30, release date: 2020-05-06, Last modification date: 2023-10-11)

Primary citation

Cruz, W.T.,Bezerra, E.H.S.,Ramos, M.V.,Rocha, B.A.M.,Medina, M.C.,Demarco, D.,Carvalho, C.P.S.,Oliveira, J.S.,Sousa, J.S.,Souza, P.F.N.,Freire, V.N.,da Silva, F.M.S.,Freitas, C.D.T.
Crystal structure and specific location of a germin-like protein with proteolytic activity from Thevetia peruviana.
Plant Sci., 298:110590-110590, 2020

PubMed Abstract: Peruvianin-I is a cysteine peptidase (EC 3.4.22) purified from Thevetia peruviana. Previous studies have shown that it is the only germin-like protein (GLP) with proteolytic activity described so far. In this work, the X-ray crystal structure of peruvianin-I was determined to a resolution of 2.15 Å (PDB accession number: 6ORM) and its specific location was evaluated by different assays. Its overall structure shows an arrangement composed of a homohexamer (a trimer of dimers) where each monomer exhibits a typical β-barrel fold and two glycosylation sites (Asn and Asn). Analysis of its active site confirmed the absence of essential amino acids for typical oxalate oxidase activity of GLPs. Details of the active site and molecular docking results, using a specific cysteine peptidase inhibitor (iodoacetamide), were used to discuss a plausible mechanism for proteolytic activity of peruvianin-I. Histological analyses showed that T. peruviana has articulated anastomosing laticifers, i.e., rows of cells which merge to form continuous tubes throughout its green organs. Moreover, peruvianin-I was detected exclusively in the latex. Because latex peptidases have been described as defensive molecules against insects, we hypothesize that peruvianin-I contributes to protect T. peruviana plants against herbivory.

PubMed: 32771148
DOI: 10.1016/j.plantsci.2020.110590

Experimental method

X-RAY DIFFRACTION (2.15 Å)