6CKH

Manduca sexta Peptidoglycan Recognition Protein-1

6CKH の概要

• エントリーDOI: 10.2210/pdb6ckh/pdb
• 分子名称: Peptidoglycan-recognition protein (2 entities in total)
• 機能のキーワード: pattern recognition receptor, peptidoglycan, innate immune system, immune system
• 由来する生物種: Manduca sexta (Tobacco hawkmoth)
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 20552.93

構造登録者

Hu, Y. (登録日: 2018-02-28, 公開日: 2019-06-05, 最終更新日: 2024-10-23)

主引用文献

Hu, Y.,Cao, X.,Li, X.,Wang, Y.,Boons, G.J.,Deng, J.,Jiang, H.
The three-dimensional structure and recognition mechanism of Manduca sexta peptidoglycan recognition protein-1.
Insect Biochem.Mol.Biol., 108:44-52, 2019

PubMed Abstract: Peptidoglycan recognition proteins (PGRPs) recognize bacteria through their unique cell wall constituent, peptidoglycans (PGs). PGRPs are conserved from insects to mammals and all function in antibacterial defense. In the tobacco hornworm Manduca sexta, PGRP1 and microbe binding protein (MBP) interact with PGs and hemolymph protease-14 precursor (proHP14) to yield active HP14. HP14 triggers a serine protease network that produces active phenoloxidase (PO), Spätzle, and other cytokines to stimulate immune responses. PGRP1 binds preferentially to diaminopimelic acid (DAP)-PGs of Gram-negative bacteria and Gram-positive Bacillus and Clostridium species than Lys-PGs of other Gram-positive bacteria. In this study, we synthesized DAP- and Lys-muramyl pentapeptide (MPP) and monitored their associations with M. sexta PGRP1 by surface plasmon resonance. The K values (0.57 μM for DAP-MPP and 45.6 μM for Lys-MPP) agree with the differential recognition of DAP- and Lys-PGs. To reveal its structural basis, we produced the PGRP1 in insect cells and determined its structure at a resolution of 2.1 Å. The protein adopts a fold similar to those from other PGRPs with a classical L-shaped PG-binding groove. A unique loop lining the shallow groove suggests a different ligand-binding mechanism. In summary, this study provided new insights into the PG recognition by PGRPs, a critical first step that initiates the serine protease cascade.

PubMed: 30905759
DOI: 10.1016/j.ibmb.2019.03.001

実験手法

X-RAY DIFFRACTION (2.1 Å)