1s2j: Difference between revisions
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New page: left|200px<br /><applet load="1s2j" size="450" color="white" frame="true" align="right" spinBox="true" caption="1s2j, resolution 2.20Å" /> '''Crystal structure of... |
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[[Image:1s2j.jpg|left|200px]]<br /><applet load="1s2j" size=" | [[Image:1s2j.jpg|left|200px]]<br /><applet load="1s2j" size="350" color="white" frame="true" align="right" spinBox="true" | ||
caption="1s2j, resolution 2.20Å" /> | caption="1s2j, resolution 2.20Å" /> | ||
'''Crystal structure of the Drosophila pattern-recognition receptor PGRP-SA'''<br /> | '''Crystal structure of the Drosophila pattern-recognition receptor PGRP-SA'''<br /> | ||
==Overview== | ==Overview== | ||
The Drosophila peptidoglycan recognition protein SA (PGRP-SA) is | The Drosophila peptidoglycan recognition protein SA (PGRP-SA) is critically involved in sensing bacterial infection and activating the Toll signaling pathway, which induces the expression of specific antimicrobial peptide genes. We have determined the crystal structure of PGRP-SA to 2.2-A resolution and analyzed its peptidoglycan (PG) recognition and signaling activities. We found an extended surface groove in the structure of PGRP-SA, lined with residues that are highly diverse among different PGRPs. Mutational analysis identified it as a PG docking groove required for Toll signaling and showed that residue Ser158 is essential for both PG binding and Toll activation. Contrary to the general belief that PGRP-SA has lost enzyme function and serves primarily for PG sensing, we found that it possesses an intrinsic L,D-carboxypeptidase activity for diaminopimelic acid-type tetrapeptide PG fragments but not lysine-type PG fragments, and that Ser158 and His42 may participate in the hydrolytic activity. As L,D-configured peptide bonds exist only in prokaryotes, this work reveals a rare enzymatic activity in a eukaryotic protein known for sensing bacteria and provides a possible explanation of how PGRP-SA mediates Toll activation specifically in response to lysine-type PG. | ||
==About this Structure== | ==About this Structure== | ||
1S2J is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Drosophila_melanogaster Drosophila melanogaster] with PO4 as [http://en.wikipedia.org/wiki/ligand ligand]. Active as [http://en.wikipedia.org/wiki/Muramoyltetrapeptide_carboxypeptidase Muramoyltetrapeptide carboxypeptidase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.4.17.13 3.4.17.13] Full crystallographic information is available from [http:// | 1S2J is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Drosophila_melanogaster Drosophila melanogaster] with <scene name='pdbligand=PO4:'>PO4</scene> as [http://en.wikipedia.org/wiki/ligand ligand]. Active as [http://en.wikipedia.org/wiki/Muramoyltetrapeptide_carboxypeptidase Muramoyltetrapeptide carboxypeptidase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.4.17.13 3.4.17.13] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1S2J OCA]. | ||
==Reference== | ==Reference== | ||
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[[Category: Muramoyltetrapeptide carboxypeptidase]] | [[Category: Muramoyltetrapeptide carboxypeptidase]] | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
[[Category: Chang, C | [[Category: Chang, C I.]] | ||
[[Category: Chelliah, Y.]] | [[Category: Chelliah, Y.]] | ||
[[Category: Deisenhofer, J.]] | [[Category: Deisenhofer, J.]] | ||
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[[Category: pi-helix (one turn)]] | [[Category: pi-helix (one turn)]] | ||
''Page seeded by [http:// | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 14:57:16 2008'' | ||
