Structural highlights
3ie5 is a 2 chain structure with sequence from Hyppe. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
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| Ligands: | , , , , , |
| Related: | |
| Gene: | hyp-1 (HYPPE) |
| Resources: | FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT |
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
Hypericin, a red-colored naphtodianthrone, is a natural product synthesized in the medicinal plant Hypericum perforatum, widely known as St. John's wort. Hypericin has been attracting a growing attention of the pharmaceutical industry because of its potential application in various therapies, including the treatment of depression. In vivo, hypericin is synthesized by dimerization of emodin in a complicated multistep reaction that is reportedly catalyzed by a small (17.8kDa) protein, Hyp-1. Based on relatively low sequence similarity ( approximately 50%), Hyp-1 has been tentatively classified as a plant PR-10 (pathogenesis-related class 10) protein. Members of the PR-10 family are ubiquitous plant proteins associated with stress control and tissue differentiation but with no clearly understood molecular mechanism. They have, however, a well-defined folding canon, consisting of an extended antiparallel beta-sheet wrapped around a C-terminal alpha-helix, enclosing in the protein interior a huge cavity, in which various hydrophobic ligands can be bound. Apart from Hyp-1, only two other PR-10 members have been found to possess enzymatic activity (S-norcoclaurine synthase and TcmN aromatase/cyclase). In this paper, we report a high-resolution crystal structure of Hyp-1, confirming that it indeed has a PR-10 fold. The protein binds multiple polyethylene glycol molecules, some of which occupy the hydrophobic cavity. The crystallographic model illustrates a high degree of conformational adaptability of both interacting partners for efficient binding. We have been unable, however, to dimerize emodin to hypericin using Hyp-1 as biocatalyst. This puzzling result does not have a clear explanation at this time.
Crystal structure of Hyp-1, a St. John's wort protein implicated in the biosynthesis of hypericin.,Michalska K, Fernandes H, Sikorski M, Jaskolski M J Struct Biol. 2010 Feb;169(2):161-71. Epub 2009 Oct 21. PMID:19853038[1]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Michalska K, Fernandes H, Sikorski M, Jaskolski M. Crystal structure of Hyp-1, a St. John's wort protein implicated in the biosynthesis of hypericin. J Struct Biol. 2010 Feb;169(2):161-71. Epub 2009 Oct 21. PMID:19853038 doi:10.1016/j.jsb.2009.10.008
