2l2b: Difference between revisions
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[[2l2b]] is a 1 chain structure with sequence from [http://en.wikipedia.org/wiki/Stichodactyla_helianthus Stichodactyla helianthus]. Full experimental information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2L2B OCA]. <br> | [[2l2b]] is a 1 chain structure with sequence from [http://en.wikipedia.org/wiki/Stichodactyla_helianthus Stichodactyla helianthus]. Full experimental information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2L2B OCA]. <br> | ||
<b>Activity:</b> <span class='plainlinks'>[http://en.wikipedia.org/wiki/Glucokinase Glucokinase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=2.7.1.2 2.7.1.2] </span><br> | <b>Activity:</b> <span class='plainlinks'>[http://en.wikipedia.org/wiki/Glucokinase Glucokinase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=2.7.1.2 2.7.1.2] </span><br> | ||
<b>Resources:</b> <span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=2l2b FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2l2b OCA], [http://www.rcsb.org/pdb/explore.do?structureId=2l2b RCSB], [http://www.ebi.ac.uk/pdbsum/2l2b PDBsum]</span><br> | |||
== Publication Abstract from PubMed == | == Publication Abstract from PubMed == | ||
Actinoporins are a family of sea anemone proteins that bind to membranes and produce functional pores which result in cell lysis. Actinoporin variants with decreased lytic activity usually show a reduced affinity for membranes. However, for some of these mutant versions there is no direct correlation between the loss of binding affinity and the decrease in their overall lytic activity, suggesting that other steps in pore formation may be hampered or facilitated by the mutations. To test this hypothesis on the mechanism of pore formation by this interesting family of proteins, structural and dynamic NMR studies have been carried out on two disabled variants of the actinoporin Sticholysin II, R29Q and Y111N. It is shown that their lytic activity is not only related to their membrane affinity but also to their conformational mechanism for membrane insertion. Alterations in their activities can be explained by structural, electrostatic and dynamic differences in a cluster of aromatic moieties and the N-terminus. In addition, the dynamic properties of some segments located at the C-terminus of the R29Q variant suggest a relevant role for this region in terms of protein-protein interactions. On the basis of all these results, we propose that R29 anchors a network of electrostatic interactions crucial for the actinoporin's approach to the membrane and that Y111 induces a necessary disorder in the loop regions that bind to membranes. | Actinoporins are a family of sea anemone proteins that bind to membranes and produce functional pores which result in cell lysis. Actinoporin variants with decreased lytic activity usually show a reduced affinity for membranes. However, for some of these mutant versions there is no direct correlation between the loss of binding affinity and the decrease in their overall lytic activity, suggesting that other steps in pore formation may be hampered or facilitated by the mutations. To test this hypothesis on the mechanism of pore formation by this interesting family of proteins, structural and dynamic NMR studies have been carried out on two disabled variants of the actinoporin Sticholysin II, R29Q and Y111N. It is shown that their lytic activity is not only related to their membrane affinity but also to their conformational mechanism for membrane insertion. Alterations in their activities can be explained by structural, electrostatic and dynamic differences in a cluster of aromatic moieties and the N-terminus. In addition, the dynamic properties of some segments located at the C-terminus of the R29Q variant suggest a relevant role for this region in terms of protein-protein interactions. On the basis of all these results, we propose that R29 anchors a network of electrostatic interactions crucial for the actinoporin's approach to the membrane and that Y111 induces a necessary disorder in the loop regions that bind to membranes. | ||
Revision as of 13:20, 30 April 2014
Structure of StnII-Y111N, a mutant of the sea anemone actinoporin Sticholysin IIStructure of StnII-Y111N, a mutant of the sea anemone actinoporin Sticholysin II
Structural highlights2l2b is a 1 chain structure with sequence from Stichodactyla helianthus. Full experimental information is available from OCA. Activity: Glucokinase, with EC number 2.7.1.2 Publication Abstract from PubMedActinoporins are a family of sea anemone proteins that bind to membranes and produce functional pores which result in cell lysis. Actinoporin variants with decreased lytic activity usually show a reduced affinity for membranes. However, for some of these mutant versions there is no direct correlation between the loss of binding affinity and the decrease in their overall lytic activity, suggesting that other steps in pore formation may be hampered or facilitated by the mutations. To test this hypothesis on the mechanism of pore formation by this interesting family of proteins, structural and dynamic NMR studies have been carried out on two disabled variants of the actinoporin Sticholysin II, R29Q and Y111N. It is shown that their lytic activity is not only related to their membrane affinity but also to their conformational mechanism for membrane insertion. Alterations in their activities can be explained by structural, electrostatic and dynamic differences in a cluster of aromatic moieties and the N-terminus. In addition, the dynamic properties of some segments located at the C-terminus of the R29Q variant suggest a relevant role for this region in terms of protein-protein interactions. On the basis of all these results, we propose that R29 anchors a network of electrostatic interactions crucial for the actinoporin's approach to the membrane and that Y111 induces a necessary disorder in the loop regions that bind to membranes. Intrinsic local disorder and a network of charge-charge interactions are key to actinoporin membrane disruption and cytotoxicity.,Pardo-Cea MA, Castrillo I, Alegre-Cebollada J, Martinez-Del-Pozo A, Gavilanes JG, Bruix M FEBS J. 2011 Apr 11. doi: 10.1111/j.1742-4658.2011.08123.x. PMID:21481191[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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