1S2J

Crystal structure of the Drosophila pattern-recognition receptor PGRP-SA

1S2J の概要

• エントリーDOI: 10.2210/pdb1s2j/pdb
• 分子名称: Peptidoglycan recognition protein SA CG11709-PA, PHOSPHATE ION (3 entities in total)
• 機能のキーワード: mixed beta-sheet, pi-helix (one turn), hydrolase
• 由来する生物種: Drosophila melanogaster (fruit fly)
• 細胞内の位置: Secreted: Q9VYX7
• タンパク質・核酸の鎖数: 2
• 化学式量合計: 46788.38

構造登録者

Chang, C.-I.,Pili-Floury, S.,Chelliah, Y.,Lemaitre, B.,Mengin-Lecreulx, D.,Deisenhofer, J. (登録日: 2004-01-08, 公開日: 2004-09-14, 最終更新日: 2024-11-20)

主引用文献

Chang, C.-I.,Pili-Floury, S.,Herve, M.,Parquet, C.,Chelliah, Y.,Lemaitre, B.,Mengin-Lecreulx, D.,Deisenhofer, J.
A Drosophila pattern recognition receptor contains a peptidoglycan docking groove and unusual l,d-carboxypeptidase activity.
PLOS BIOL., 2:1293-1302, 2004

PubMed Abstract: 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.

PubMed: 15361936
DOI: 10.1371/journal.pbio.0020277

実験手法

X-RAY DIFFRACTION (2.2 Å)