1OKH

Viscotoxin A3 from Viscum album L.

Summary for 1OKH

• Entry DOI: 10.2210/pdb1okh/pdb
• Descriptor: VISCOTOXIN A3, PHOSPHATE ION, SULFATE ION, ... (4 entities in total)
• Functional Keywords: thionin, toxin, plant defense
• Biological source: VISCUM ALBUM (EUROPEAN MISTLETOE)
• Total number of polymer chains: 2
• Total formula weight: 9971.26

Authors

Debreczeni, J.E.,Girmann, B.,Zeeck, A.,Sheldrick, G.M. (deposition date: 2003-07-24, release date: 2003-12-04, Last modification date: 2019-07-24)

Primary citation

Debreczeni, J.E.,Girmann, B.,Zeeck, A.,Kratzner, R.,Sheldrick, G.M.
Structure of Viscotoxin A3: Disulfide Location from Weak Sad Data
Acta Crystallogr.,Sect.D, 59:2125-, 2003

PubMed Abstract: The crystal structure of viscotoxin A3 (VT A3) extracted from European mistletoe (Viscum album L.) has been solved using the anomalous diffraction of the native S atoms measured in-house with Cu Kalpha radiation to a resolution of 2.2 A and truncated to 2.5 A. A 1.75 A resolution synchrotron data set was used for phase expansion and refinement. An innovation in the dual-space substructure-solution program SHELXD enabled the individual S atoms of the disulfide bonds to be located using the Cu Kalpha data; this resulted in a marked improvement in the phasing compared with the use of super-S atoms. The VT A3 monomer consists of 46 amino acids with three disulfide bridges and has an overall fold resembling the canonical architecture of the alpha- and beta-thionins, a capital letter L. The asymmetric unit consists of two monomers related by a local twofold axis and held together by hydrophobic interactions between the monomer units. One phosphate anion (confirmed by 31P-NMR and MS) is associated with each monomer.

PubMed: 14646070
DOI: 10.1107/S0907444903018973

Experimental method

X-RAY DIFFRACTION (1.75 Å)