PDBsum entry 4m5e

Hydrolase

PDB id: 4m5e

Contents

Protein chain

405 a.a.

Ligands

GOL ×3

Metals

_CA ×4

_CD

Waters ×471

PDB id:

4m5e

Name:

Hydrolase

Title:

Tse3 structure

Structure:

Uncharacterized protein. Chain: a. Fragment: unp residues 1-402. Engineered: yes

Source:

Pseudomonas aeruginosa. Organism_taxid: 208964. Strain: atcc 15692 / pao1 / 1c / prs 101 / lmg 12228. Gene: pa3484. Expressed in: escherichia coli. Expression_system_taxid: 562

Resolution:

1.49Å R-factor: 0.181 R-free: 0.199

Authors:

Y.Qian

Key ref:

D.Lu et al. (2014). Structural insights into the T6SS effector protein Tse3 and the Tse3-Tsi3 complex from Pseudomonas aeruginosa reveal a calcium-dependent membrane-binding mechanism. Mol Microbiol, 92, 1092-1112. PubMed id: 24724564 DOI: 10.1111/mmi.12616

Date:

08-Aug-13 Release date: 23-Apr-14

Protein chain

Q9HYC5  (TSE3_PSEAE) -  Peptidoglycan muramidase Tse3 from Pseudomonas aeruginosa (strain ATCC 15692 / DSM 22644 / CIP 104116 / JCM 14847 / LMG 12228 / 1C / PRS 101 / PAO1)

Seq: 408 a.a.

Struc: 405 a.a.*

* PDB and UniProt seqs differ at 4 residue positions (black crosses)

Enzyme reactions

• Enzyme class: E.C.3.2.1.17 - lysozyme.
• Reaction: Hydrolysis of the 1,4-beta-linkages between N-acetyl-D-glucosamine and N-acetylmuramic acid in peptidoglycan heteropolymers of the prokaryotes cell walls.

DOI no: 10.1111/mmi.12616

Mol Microbiol 92:1092-1112 (2014)

PubMed id: 24724564

Structural insights into the T6SS effector protein Tse3 and the Tse3-Tsi3 complex from Pseudomonas aeruginosa reveal a calcium-dependent membrane-binding mechanism.

D.Lu, G.Shang, H.Zhang, Q.Yu, X.Cong, J.Yuan, F.He, C.Zhu, Y.Zhao, K.Yin, Y.Chen, J.Hu, X.Zhang, Z.Yuan, S.Xu, W.Hu, H.Cang, L.Gu.

ABSTRACT

The opportunistic pathogen Pseudomonas aeruginosa uses the type VI secretion system (T6SS) to deliver the muramidase Tse3 into the periplasm of rival bacteria to degrade their peptidoglycan (PG). Concomitantly, P. aeruginosa uses the periplasm-localized immunity protein Tsi3 to prevent potential self-intoxication caused by Tse3, and thus gains an edge over rival bacteria in fierce niche competition. Here, we report the crystal structures of Tse3 and the Tse3-Tsi3 complex. Tse3 contains an annexin repeat-like fold at the N-terminus and a G-type lysozyme fold at the C-terminus. One loop in the N-terminal domain (Loop 12) and one helix (α9) from the C-terminal domain together anchor Tse3 and the Tse3-Tsi3 complex to membrane in a calcium-dependent manner in vitro, and this membrane-binding ability is essential for Tse3's activity. In the C-terminal domain, a Y-shaped groove present on the surface likely serves as the PG binding site. Two calcium-binding motifs are also observed in the groove and these are necessary for Tse3 activity. In the Tse3-Tsi3 structure, three loops of Tsi3 insert into the substrate-binding groove of Tse3, and three calcium ions present at the interface of the complex are indispensable for the formation of the Tse3-Tsi3 complex.