Structural highlights
Function
[ML1_VISAL] The A chain is responsible for inhibiting protein synthesis through the catalytic inactivation of 60S ribosomal subunits by removing adenine from position 4,324 of 28S rRNA. The B chain binds to cell receptors and probably facilitates the entry into the cell of the A chain; B chains are also responsible for cell agglutination (lectin activity). Inhibits growth of the human tumor cell line Molt4.[1] [2] [3]
Evolutionary Conservation
Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf.
Publication Abstract from PubMed
The crystal structure of mistletoe lectin I (ML-I) isolated from the European mistletoe Viscum album in complex with the most active phytohormone zeatin has been analyzed and refined to 2.54 A resolution. X-ray suitable crystals of ML-I were obtained by the counter-diffusion method using the Gel-Tube R crystallization kit (GT-R) onboard the Russian Service Module on the international space station ISS. High quality hexagonal bipyramidal crystals were grown during 3 months under microgravity conditions. Selected crystals were soaked in a saturated solution of zeatin and subsequently diffraction data were collected applying synchrotron radiation. A distinct F(o)-F(c) electron density has been found inside a binding pocket located in subunit B of ML-I and has been interpreted as a single zeatin molecule. The structure was refined to investigate the zeatin-ML-I interactions in detail. The results demonstrate the ability of mistletoe to protect itself from the host transpiration regulation by absorbing the most active host plant hormones as part of a defense mechanism.
Structure of mistletoe lectin I from Viscum album in complex with the phytohormone zeatin.,Meyer A, Rypniewski W, Szymanski M, Voelter W, Barciszewski J, Betzel C Biochim Biophys Acta. 2008 Nov;1784(11):1590-5. Epub 2008 Jul 31. PMID:18718563[4]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Kourmanova AG, Soudarkina OJ, Olsnes S, Kozlov JV. Cloning and characterization of the genes encoding toxic lectins in mistletoe (Viscum album L). Eur J Biochem. 2004 Jun;271(12):2350-60. PMID:15182350 doi:http://dx.doi.org/10.1111/j.1432-1033.2004.04153.x
- ↑ Mishra V, Sharma RS, Yadav S, Babu CR, Singh TP. Purification and characterization of four isoforms of Himalayan mistletoe ribosome-inactivating protein from Viscum album having unique sugar affinity. Arch Biochem Biophys. 2004 Mar 15;423(2):288-301. PMID:15001393 doi:http://dx.doi.org/10.1016/j.abb.2003.12.033
- ↑ Dietrich JB, Ribereau-Gayon G, Jung ML, Franz H, Beck JP, Anton R. Identity of the N-terminal sequences of the three A chains of mistletoe (Viscum album L.) lectins: homology with ricin-like plant toxins and single-chain ribosome-inhibiting proteins. Anticancer Drugs. 1992 Oct;3(5):507-11. PMID:1450445
- ↑ Meyer A, Rypniewski W, Szymanski M, Voelter W, Barciszewski J, Betzel C. Structure of mistletoe lectin I from Viscum album in complex with the phytohormone zeatin. Biochim Biophys Acta. 2008 Nov;1784(11):1590-5. Epub 2008 Jul 31. PMID:18718563 doi:10.1016/j.bbapap.2008.07.010
