1w15
From Proteopedia
| Line 5: | Line 5: | ||
==Overview== | ==Overview== | ||
| - | The neuronal protein synaptotagmin 1 functions as a Ca(2+) sensor in, exocytosis via two Ca(2+)-binding C(2) domains. The very similar, synaptotagmin 4, which includes all the predicted Ca(2+)-binding residues, in the C(2)B domain but not in the C(2)A domain, is also thought to, function as a neuronal Ca(2+) sensor. Here we show that, unexpectedly, both C(2) domains of fly synaptotagmin 4 exhibit Ca(2+)-dependent, phospholipid binding, whereas neither C(2) domain of rat synaptotagmin 4, binds Ca(2+) or phospholipids efficiently. Crystallography reveals that, changes in the orientations of critical Ca(2+) ligands, and perhaps their, flexibility, render the rat synaptotagmin 4 C(2)B domain unable to form, full Ca(2+)-binding sites. These results indicate that synaptotagmin 4 is, a Ca(2+) | + | The neuronal protein synaptotagmin 1 functions as a Ca(2+) sensor in, exocytosis via two Ca(2+)-binding C(2) domains. The very similar, synaptotagmin 4, which includes all the predicted Ca(2+)-binding residues, in the C(2)B domain but not in the C(2)A domain, is also thought to, function as a neuronal Ca(2+) sensor. Here we show that, unexpectedly, both C(2) domains of fly synaptotagmin 4 exhibit Ca(2+)-dependent, phospholipid binding, whereas neither C(2) domain of rat synaptotagmin 4, binds Ca(2+) or phospholipids efficiently. Crystallography reveals that, changes in the orientations of critical Ca(2+) ligands, and perhaps their, flexibility, render the rat synaptotagmin 4 C(2)B domain unable to form, full Ca(2+)-binding sites. These results indicate that synaptotagmin 4 is, a Ca(2+) sensor in the fly but not in the rat, that the Ca(2+)-binding, properties of C(2) domains cannot be reliably predicted from sequence, analyses, and that proteins clearly identified as orthologs may, nevertheless have markedly different functional properties. |
==About this Structure== | ==About this Structure== | ||
| - | 1W15 is a | + | 1W15 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Rattus_norvegicus Rattus norvegicus] with CA, NA and CL as [http://en.wikipedia.org/wiki/ligands ligands]. Structure known Active Site: AC1. Full crystallographic information is available from [http://ispc.weizmann.ac.il/oca-bin/ocashort?id=1W15 OCA]. |
==Reference== | ==Reference== | ||
| Line 29: | Line 29: | ||
[[Category: transmembrane]] | [[Category: transmembrane]] | ||
| - | ''Page seeded by [http://ispc.weizmann.ac.il/oca OCA ] on | + | ''Page seeded by [http://ispc.weizmann.ac.il/oca OCA ] on Mon Nov 5 14:20:32 2007'' |
Revision as of 12:15, 5 November 2007
|
RAT SYNAPTOTAGMIN 4 C2B DOMAIN IN THE PRESENCE OF CALCIUM
Overview
The neuronal protein synaptotagmin 1 functions as a Ca(2+) sensor in, exocytosis via two Ca(2+)-binding C(2) domains. The very similar, synaptotagmin 4, which includes all the predicted Ca(2+)-binding residues, in the C(2)B domain but not in the C(2)A domain, is also thought to, function as a neuronal Ca(2+) sensor. Here we show that, unexpectedly, both C(2) domains of fly synaptotagmin 4 exhibit Ca(2+)-dependent, phospholipid binding, whereas neither C(2) domain of rat synaptotagmin 4, binds Ca(2+) or phospholipids efficiently. Crystallography reveals that, changes in the orientations of critical Ca(2+) ligands, and perhaps their, flexibility, render the rat synaptotagmin 4 C(2)B domain unable to form, full Ca(2+)-binding sites. These results indicate that synaptotagmin 4 is, a Ca(2+) sensor in the fly but not in the rat, that the Ca(2+)-binding, properties of C(2) domains cannot be reliably predicted from sequence, analyses, and that proteins clearly identified as orthologs may, nevertheless have markedly different functional properties.
About this Structure
1W15 is a Single protein structure of sequence from Rattus norvegicus with CA, NA and CL as ligands. Structure known Active Site: AC1. Full crystallographic information is available from OCA.
Reference
Structural basis for the evolutionary inactivation of Ca2+ binding to synaptotagmin 4., Dai H, Shin OH, Machius M, Tomchick DR, Sudhof TC, Rizo J, Nat Struct Mol Biol. 2004 Sep;11(9):844-9. Epub 2004 Aug 15. PMID:15311271
Page seeded by OCA on Mon Nov 5 14:20:32 2007
Categories: Rattus norvegicus | Single protein | Dai, H. | Machius, M. | Rizo, J. | Shin, O.H. | Sudhof, T.C. | Tomchick, D.R. | CA | CL | NA | Calcium | Endocytosis/exocytosis | Neurotransmitter release | Synaptotagmin | Transmembrane
