Biological Assembly 1  

 3D View: Structure

Global Symmetry: Asymmetric - C1 
Global Stoichiometry: Monomer - A1 

Biological assembly 1 assigned by authors.

Macromolecule Content

• Total Structure Weight: 14.29 kDa 
• Atom Count: 1009 
• Residue Count: 131 
• Unique protein chains: 1

2M2K

The structure of HasB CTD

• DOI: 10.2210/pdb2M2K/pdb
• BMRB: 15440

• Classification: TRANSPORT PROTEIN
• Organism(s): Serratia marcescens
• Expression System: Escherichia coli
• Mutation(s): No 


• Deposited: 2012-12-26 Released: 2013-04-10 
• Deposition Author(s): Prochnicka-Chalufour, A., Lefevre, J., Simenel, C., Delepelaire, P., Wandersman, C., Delepierre, M., Izadi-Pruneyre, N.

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Experimental Data Snapshot

• Method: SOLUTION NMR
• Conformers Calculated: 500 
• Conformers Submitted: 20 
• Selection Criteria: structures with the lowest energy 

Literature

The Structure of HasB Reveals a New Class of TonB Protein Fold.

de Amorim, G.C., Prochnicka-Chalufour, A., Delepelaire, P., Lefevre, J., Simenel, C., Wandersman, C., Delepierre, M., Izadi-Pruneyre, N.

(2013) PLoS One 8: e58964-e58964

• PubMed: 23527057 
• DOI: 10.1371/journal.pone.0058964
• Structures With Same Primary Citation


• PubMed Abstract: 
  

TonB is a key protein in active transport of essential nutrients like vitamin B12 and metal sources through the outer membrane transporters of Gram-negative bacteria. This inner membrane protein spans the periplasm, contacts the outer membrane receptor by its periplasmic domain and transduces energy from the cytoplasmic membrane pmf to the receptor allowing nutrient internalization. Whereas generally a single TonB protein allows the acquisition of several nutrients through their cognate receptor, in some species one particular TonB is dedicated to a specific system. Despite a considerable amount of data available, the molecular mechanism of TonB-dependent active transport is still poorly understood. In this work, we present a structural study of a TonB-like protein, HasB dedicated to the HasR receptor. HasR acquires heme either free or via an extracellular heme transporter, the hemophore HasA. Heme is used as an iron source by bacteria. We have solved the structure of the HasB periplasmic domain of Serratia marcescens and describe its interaction with a critical region of HasR. Some important differences are observed between HasB and TonB structures. The HasB fold reveals a new structural class of TonB-like proteins. Furthermore, we have identified the structural features that explain the functional specificity of HasB. These results give a new insight into the molecular mechanism of nutrient active transport through the bacterial outer membrane and present the first detailed structural study of a specific TonB-like protein and its interaction with the receptor.

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Organizational Affiliation: 

Institut Pasteur, Unité de Résonance Magnétique Nucléaire des Biomolécules, Département de Biologie Structurale et Chimie, Paris, France.

Macromolecules

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details
HasB protein	A	131	Serratia marcescens	Mutation(s): 0  Gene Names: hasB
Find proteins for Q79AD1 (Serratia marcescens) Go to UniProtKB:  Q79AD1

Experimental Data & Validation

Experimental Data

• Method: SOLUTION NMR
• Conformers Calculated: 500 
• Conformers Submitted: 20 
• Selection Criteria: structures with the lowest energy 
• OLDERADO: 2M2K Olderado

Structure Validation

Entry History 

Deposition Data

• Deposited Date: 2012-12-26 
• Released Date: 2013-04-10 
Deposition Author(s): Prochnicka-Chalufour, A., Lefevre, J., Simenel, C., Delepelaire, P., Wandersman, C., Delepierre, M., Izadi-Pruneyre, N.

Revision History 

• Version 1.0: 2013-04-10
  Type: Initial release