title: Crystallization and preliminary X-ray diffraction studies of the cysteine protease ervatamin A from Ervatamia coronaria.
abstract: The ervatamins are highly stable cysteine proteases that are present in the latex of the medicinal plant Ervatamia coronaria and belong to the papain family, members of which share similar amino-acid sequences and also a similar fold comprising two domains. Ervatamin A from this family, a highly active protease compared with others from the same source, has been purified to homogeneity by ion-exchange chromatography and crystallized by the vapour-diffusion method. Needle-shaped crystals of ervatamin A diffract to 2.1 A resolution and belong to space group C222(1), with unit-cell parameters a = 31.10, b = 144.17, c = 108.61 A. The solvent content using an ervatamin A molecular weight of 27.6 kDa is 43.9%, with a VM value of 2.19 A3 Da(-1) assuming one protein molecule in the asymmetric unit. A molecular-replacement solution has been found using the structure of ervatamin C as a search model.
authors.affiliation: Saha Institue of Nuclear Physics, Crystallography and Molecular Biology Division, 1/AF Bidhannagar, Kolkata 700 064, India.
authors.forename: Sibani
authors.initials: S
authors.lastname: Chakraborty
authors.forename: Sampa
authors.initials: S
authors.lastname: Biswas
authors.forename: Chandana
authors.initials: C
authors.lastname: Chakrabarti
authors.forename: Jiban K
authors.initials: JK
authors.lastname: Dattagupta
mesh_terms: D003001:Cloning, Molecular / Q000379:methods; D003460:Crystallization / Q000379:methods; D003546:Cysteine Endopeptidases / Q000737:chemistry* / Q000302:isolation & purification; D010940:Plant Proteins / Q000737:chemistry / Q000302:isolation & purification; D010946:Plants, Medicinal / Q000737:chemistry*; D014835:Volatilization; D014961:X-Ray Diffraction
chemical_list: D010940:Plant Proteins; D003546:Cysteine Endopeptidases; C116225:ervatamin