PDBsum entry 2obl

Hydrolase

PDB id: 2obl

Contents

Protein chain

346 a.a. *

Ligands

ACT

IMD

Metals

_CA

Waters ×232

* Residue conservation analysis

PDB id:

2obl

Name:

Hydrolase

Title:

Structural and biochemical analysis of a prototypical atpase from the type iii secretion system of pathogenic bacteria

Structure:

Escn. Chain: a. Fragment: c-terminal domain, residues 103-446. Engineered: yes. Mutation: yes

Source:

Escherichia coli o127:h6. Organism_taxid: 574521. Strain: e2348/69. Gene: escn. Expressed in: escherichia coli bl21. Expression_system_taxid: 511693.

Resolution:

1.80Å R-factor: 0.197 R-free: 0.232

Authors:

R.Zarivach,M.Vuckovic,W.Deng,B.B.Finlay,N.C.J.Strynadka

Key ref:

R.Zarivach et al. (2007). Structural analysis of a prototypical ATPase from the type III secretion system. Nat Struct Mol Biol, 14, 131-137. PubMed id: 17237797 DOI: 10.1038/nsmb1196

Date:

19-Dec-06 Release date: 30-Jan-07

Protein chain

B7UMA6  (B7UMA6_ECO27) -  protein-secreting ATPase from Escherichia coli O127:H6 (strain E2348/69 / EPEC)

Seq: 446 a.a.

Struc: 346 a.a.*

* PDB and UniProt seqs differ at 3 residue positions (black crosses)

Enzyme reactions

• Enzyme class: E.C.7.4.2.8 - protein-secreting ATPase.
• Reaction: ATP + H2O + cellular proteinSide 1 = ADP + phosphate + cellular proteinSide 2

Molecule diagrams generated from .mol files obtained from the KEGG ftp site

reference

DOI no: 10.1038/nsmb1196

Nat Struct Mol Biol 14:131-137 (2007)

PubMed id: 17237797

Structural analysis of a prototypical ATPase from the type III secretion system.

R.Zarivach, M.Vuckovic, W.Deng, B.B.Finlay, N.C.Strynadka.

ABSTRACT

The type III secretion system (T3SS) ATPase is the conserved and essential inner-membrane component involved in the initial stages of selective secretion of specialized T3SS virulence effector proteins from the bacterial cytoplasm through to the infected host cell, a process crucial to subsequent pathogenicity. Here we present the 1.8-A-resolution crystal structure of the catalytic domain of the prototypical T3SS ATPase EscN from enteropathogenic Escherichia coli (EPEC). Along with in vitro and in vivo mutational analysis, our data show that the T3SS ATPases share similarity with the F1 ATPases but have important structural and sequence differences that dictate their unique secretory role. We also show that T3SS ATPase activity is dependent on EscN oligomerization and describe the molecular features and possible functional implications of a hexameric ring model.

Selected figure(s)

Figure 5.
Figure 5. Functional mutants of EscN. (a) Previously isolated functional mutants of the Salmonella ATPase InvC (blue) mapped on the structure of EscN with bound ATP (gold), delineating the position of the active site. See Supplementary Figure 2 for the corresponding numbering in Salmonella. (b) Functional mutants created and characterized in this study. Shown are V393P (yellow) and the mutation of the active site residue that cooperatively binds the ATP of the adjacent monomer, Arg366 (blue).

Figure 6.
Figure 6. The hexameric T3SS and F1 ATPases. Right, the [3] [3] heterohexamer of the F1 ATPase, with known membrane orientation delineated by the binding of its membrane-anchored -subunit (purple) within the inner pore of the ATPase hexameric ring. In yellow is the helical domain at the C terminus of the F1 ATPases, which is absent in EscN. Left, the EscN homohexamer (blue), with the predicted docking site for the helical T3SS chaperone (PDB 1XKP^41; red), in complex with its cognate and partially unfolded effector (green). The functional point mutation V393P lies at the edge of the chaperone-binding surface (yellow).

The above figures are reprinted by permission from Macmillan Publishers Ltd: Nat Struct Mol Biol (2007, 14, 131-137) copyright 2007.

Figures were selected by an automated process.